Preschoolers Make Fewer Errors on an Object Categorization Task in the Presence of a Dog

ABSTRACT

Previous research has shown that the presence of a dog can positively impact the speed at which preschoolers perform motor skills tasks and also their ability to adhere to instructions. The current study focused on the execution of a cognitive task—object categorization—by developmentally delayed and typical preschool children in the presence of a real dog, a stuffed dog, or a human. The real dog involved in this study was a Miniature Poodle. The children (n = 12) were asked to complete a match-to-sample task in which they had to choose a picture of an object that “goes with” another. Three categories of object exemplars were used: taxonomic, thematic, and irrelevant. The presence of the real dog resulted in significantly fewer irrelevant choices than either the stuffed dog or the human conditions. Additionally, results in this experiment were consistent with previous research, showing a developmental shift where younger children were more likely to make taxonomic than thematic choices, with the reverse true of the older children. These results indicate that the presence of the real dog does not appear to alter typical performance patterns seen in object categorization, but the fact that fewer errors were made in the presence of the dog indicates that the presence of the dog does have a positive impact on performance of this cognitive task. The authors discuss several possible explanations for this outcome.     

Preschoolers Categorize Animate Objects Better in the Presence of a Dog

ABSTRACT

The current study was designed to examine whether preschool children categorize picture stimuli differentially in the presence of a real dog compared with a stuffed dog or a human. Seventeen preschool children (age in months; M = 51.67, SD = 8.06), both Typical and those with a developmental delay (“Identified”), were asked to categorize Animate and Inanimate objects into two environments (Farm and Ocean) in each of three Collaborator conditions (Real Dog, Stuffed Dog, and Human). As predicted, there was a main effect of animation: the children more accurately categorized Animate (e.g., cow) exemplars than Inanimate ones (e.g., tractor). Additionally, the Animation variable interacted with Collaborator, such that in the presence of the real dog the impact of animation was significant, but this effect was not significant in the presence of the stuffed dog or human. This result indicates that the presence of the real dog served as a highly salient stimulus which encouraged the children to focus more of their attention on other animate objects in the list. This result provides additional evidence that the presence of a dog helps preschool children to restrict their attention to the demands of the task. This is a new and interesting finding that indicates that the presence of a real dog does have an impact on cognitive task performance.     

The Role of Therapy Dogs in Speed and Accuracy to Complete Motor Skills Tasks for Preschool Children

ABSTRACT

The purpose of this study was to determine whether the presence of a therapy dog would affect the performance of a set of gross motor skills tasks for a mixed group of language-impaired and typical preschool children. The 14 children in the group were between four and six years old (four female and ten male); the two dogs were Miniature Poodles. The design was a two-way mixed model factorial, where a series of 10 gross motor skills tasks (e.g., long jump, high jump—labeled Type of Task) performed by the children served as one variable, and the presence or absence of the therapy dog (labeled Dog Presence) served as the other variable. In the dog-present conditions, the dog either performed the task immediately prior to, or at the same time as, the child. Time to complete each task and the accuracy of task performance as determined by a rating scale were determined from a review of experiment videotapes. The main effect of Dog Presence was significant (F_(1,36) = 7.471, p < 0.05, R² = 0.17). As predicted, the children completed the tasks faster when the dog was present (M = 10.88 s,SD = 9.84) than when the dog was absent (M = 13.86 s,SD = 12.64), but this effect was not present in the ratings data. This indicates that the presence of a therapy dog served as an effective motivator for the children, who performed faster, but without compromising accuracy, in all tasks but one. The interaction between dog presence and type of task was also significant (F_(9,71) = 3.67, p < 0.05, R² = 0.32) in the ratings data, indicating that the presence of the dog increased performance accuracy in some types of tasks, while decreasing it in others. Based on these results and the strong connection between motor skills and language development, the authors recommend a role for therapy dogs in speech and language development programs for preschool children.     

News & Analyses

ABSTRACT

The purpose of this study was to examine preschoolers' (n = 11) ability to follow instructions in the presence or absence of a real dog while executing a variety of motor skills tasks. These tasks were divided into one of three general classifications: 1) Modeling Tasks: the children were asked to emulate the behavior of a model, 2) Competition Tasks: the children were asked to do the task faster than a competitor, and 3) Tandem Tasks: the children were asked to do the tasks at the same time as a co-performer. Typical and Identified (language impaired) preschool children were randomly assigned to perform five tasks of each general classification alone, with a human, with a real dog, and with a stuffed dog that was similar in size and appearance to the live dog. Two independent raters rated each child's adherence to instructions (interrater reliability = 0.99) on a 7-point scale. A significant interaction between task classification and type of co-performer revealed that in the Modeling Tasks the preschoolers adhered better to the instructions when the real dog was present relative to the other conditions. In the Tandem Tasks the children adhered to instructions best when they performed the task with a human, followed by the stuffed dog (as manipulated by a human), the real dog, and worst when they were asked to perform the tasks alone. The type of co-performer made no significant difference in the Competition Tasks. These results indicate the presence of a real dog tends to be beneficial for promoting preschoolers' compliance with instructions in motor skills tasks that require modeling behavior, but not in those tasks that stress competition or those performed in tandem.     

Turning the Page for Spot: The Potential of Therapy Dogs to Support Reading Motivation Among Young Children

ABSTRACT

This study investigated whether dogs might facilitate a context conducive to reading for children when they are faced with a challenging reading passage. A within-subjects design was used to assess children’s motivation to read in two conditions: with a therapy dog and without a therapy dog. Seventeen children (8 girls; 9 boys) in Grades 1 to 3 (aged 6–8 years) and their parents participated in this study. Results of a multivariate repeated-measures ANOVA with two levels suggested that the presence of a therapy dog positively impacted children’s reading motivation and persistence when they were faced with the task of reading a challenging passage. Specifically, children confirmed feeling significantly more interested and more competent when reading in the presence (versus absence) of a therapy dog. Additionally, participants spent significantly more time reading in the presence of the therapy dog than when they read without the therapy dog present. To the best of our knowledge, this study is the first to use a within-subjects design to explore children’s reading motivation and reading persistence during a canine-assisted reading task. Moreover, as canine-assisted reading interventions assume that the reading context is one that may present a challenge, this research is unique because the reading passages were carefully selected and assigned to each participant to ensure that each child was provided with a challenging reading task. This research holds implications for the development of a gold-standard canine-assisted intervention for young struggling readers.     

Heart Rate Variability During a Working Memory Task: Does Touching a Dog or Person Affect the Response?

The presence of a dog has been associated with reduced responses to stressors in several, but not all, previous studies. The presence of a dog has also been related to improved performance on some cognitive tasks. The current study was designed to evaluate the effect of touching a dog on stress responses to a working memory task (WMT). Heart rate variability (HRV) responses to a WMT while touching a dog were compared with responses while touching a stuffed dog and a person. HRV was recorded while 53 university students aged 18 to 41 years sat on the floor next to a randomly assigned co-participant (real dog, stuffed dog, or human) and listened to a reading before and after completing a WMT. This procedure was repeated with the two other co-participants, in a randomized block order. All participants wore an HRV monitor and placed their non-dominant hand on the co-participant throughout the appropriate phase. The WMT involved pointing to increasingly complicated sequences of geometric shapes until the participant failed three times at one level. Linear mixed models analysis for nested data revealed that the memory task was stressful, with parasympathetic nervous system arousal significantly lower during the memory task than the preor post-memory listening tasks (rMSSD: ps < 0.001, = 0.023; high frequency: ps < 0.001, = 0.001). Neither of the measures differed significantly among the three conditions. There also were no significant interactions, indicating that the stress response to the memory task did not differ when the participants were touching the three different co-participants. Touching a dog did not reduce arousal in response to a stressful memory task. This research suggests that a dog may not be effective at reducing stress responses to this type of stressor. Another possibility is that the presence of a dog is more effective than touching a dog at reducing stress responses. Further investigation will be required to evaluate these possibilities.     

Differential roles of distracters in reflexive and memory-based localization

We investigated the effects of spatial and temporal factors on manual localization of a visual target by measuring accuracy, precision, and bias. Spatial factors included manipulation of display as with or without distracters, with invariant or variant distracters, and with near or far distracters, respectively, in Experiments 1, 2, and 3. The target and distracters were of 1degrees dots differing only by luminance parameter; they were presented concurrently for 150 or 1000 ms while observers had to memorize the target location maintaining a fixed gaze. The observers' task was to reproduce the location of the target with a mouse cursor available 150 ms following stimuli offset. Results from all experiments showed that localization performance for a briefly exposed target was as accurate and precise as that for a long exposed target. Moreover, manipulation of spatial factors had no systematic effects on accuracy and precision except that near distracters yielded higher precision. Interestingly, localization performance was unbiased in 150 ms condition when there were distracters in the display, while being biased towards the fovea in 1000 ms condition regardless of their presence or absence. These results suggest a temporal dynamics in dominance-suppression between egocentric and exocentric cues in the construction of memory for location.     

Set-size effects for spatial frequency change and discrimination in multiple targets

In visual search tasks with a near-threshold target amongst distracters, log detection thresholds rise in proportion to the log of the number of stimuli. Previous research has shown a very steep slope for this set-size effect where the target is a change in spatial frequency (SF) across an ISI, suggesting a low-level explanation for 'change blindness (Wright et al., 2000). Here, we analyse stimulus and task variables in order to determine the contributions of stimulus detection and attention processes. Stimuli consisted of two 150 ms frames each containing 1 to 4 Gabor targets, with an ISI of 250 ms. In a 2AFC detection task with uniform distracters, slopes of 0.23-0.52 were found, in line with visual search results. 2AFC SF discrimination tasks gave slopes of 0.68, 0.69 with homogeneous distracters and 0.76-0.96 with inhomogeneous distracters, consistent with averaging of stimuli within a frame. If the distracters were also made to change across ISI, averaging was impossible, and focal attention was required to solve the discrimination. This always gave set-size slopes > 1. It is concluded that, under conditions where a stimulus array can be analysed globally, change detection performance is limited by signal detection mechanisms, rather than limited capacity attention or memory mechanisms. However, where this is prevented, for example by changing more than one item, limitations due to attention or memory produce an even steeper set-size effect.     

Electrophysiological evidence for immature processing capacity and filtering in visuospatial working memory in adolescents

The present study investigated the development of visuospatial working memory (VSWM) capacity and the efficiency of filtering in VSWM in adolescence. To this end, a group of IQ-matched adults and adolescents performed a VSWM change detection task with manipulations of WM-load and distraction, while performance and electrophysiological contralateral delay activity (CDA) were measured. The CDA is a lateralized ERP marker of the number of targets and distracters that are selectively encoded/maintained in WM from one hemifield of the memory display. Significantly lower VSWM-capacity (Cowan's K) was found in adolescents than adults, and adolescents' WM performance (in terms of accuracy and speed) also suffered more from the presence of distracters. Distracter-related CDA responses were partly indicative of higher distracter encoding/maintenance in WM in adolescents and were positively correlated with performance measures of distracter interference. This correlation suggests that the higher interference of distracters on WM performance in adolescents was caused by an inability to block distracters from processing and maintenance in WM. The lower visuospatial WM-capacity (K) in adolescents in the high load (3 items) condition was accompanied by a trend (p<.10) towards higher CDA amplitudes in adolescents than adults, whereas CDA amplitudes in the low load (1 item) condition were comparable between adolescents and adults. These findings point to immaturity of frontal-parietal WM-attention networks that support visuospatial WM processing in adolescence.     

Sleep Deprivation in the Dark Period Does Not Impair Memory in OF1 Mice

There is increasing evidence that sleep facilitates memory acquisition and consolidation. Moreover, the sleep-wake history preceding memory acquisition and retention as well as circadian timing may be important. We showed previously that sleep deprivation (SD) following learning in OF1 mice impaired their performance on an object recognition task. The learning task was scheduled at the end of the 12 h dark period and the test 24 h later. To investigate the influence of the prominent circadian sleep-wake distribution typical for rodents, we now scheduled the learning task at the beginning of the dark period. Wakefulness following immediately after the learning task was attained either by gentle interference (SD; n?=?20) or by spontaneous wheel running (RW; n?=?20). Two control groups were used: one had no RW throughout the experiment (n?=?23), while the other group's wheel was blocked immediately after acquisition (n?=?16), thereby preventing its use until testing. Recognition memory, defined as the difference in exploration of a novel and of familiar objects, was assessed 24 h later during the test phase. Motor activity and RW use were continuously recorded. Remarkably, performance on the object recognition task was not influenced by the protocols; the waking period following acquisition did not impair memory, independent of the method inducing wakefulness (i.e., sleep deprivation or spontaneous running). Thus, all groups explored the novel object significantly longer than the familiar ones during the test phase. Interestingly, neither the amount of rest lost during the SD interventions nor the amount of rest preceding acquisition influenced performance. However, the total amount of rest obtained by the control and SD mice subjected to acquisition at “dark offset” correlated positively (r?=?0.66) with memory at test, while no such relationship occurred in the corresponding groups tested at dark onset. Neither the amount of running nor intermediate rest correlated with performance at test in the RW group. We conclude that interfering with sleep during the dark period does not affect object recognition memory consolidation.     

Methodological issues in studying the anxiety-reducing effects of animals: Reflections from a pediatric dental study

Abstract

This article reports observations made during a study investigating the role of a therapy dog in reducing anxiety in urban children visiting the dentist. The design and execution of the study were affected by methodological issues such as the reaction of urban children to the dog in the clinic, the tools used to measure anxiety in the children, the age and pet-ownership status of the children, and the personality of the therapy dog. Suggestions made for researchers designing similar studies include allowing children to become comfortable with the therapy dog before beginning formal data collection, working with younger children who have made fewer visits to the dentist, and using or developing more accurate tools for measuring behavioral and physiological anxiety.     

Strain differences in activity and emotionality do not account for differences in learning and memory performance between C57BL/6 and DBA/2 mice

This study examined emotionality, activity, learning and memory, as well as the influence of emotionality and activity on learning and memory performance in C57BL/6 and DBA/2 mice using a mouse-test battery. DBA/2 mice performed more poorly than C57BL/6 mice in complex learning tasks such as the water maze and object recognition tasks. In contrast, C57BL/6 mice showed attenuated habituation to novelty in the open field apparatus and poorer performance in the step-down passive avoidance task. The C57BL/6 mice were less exploratory and more anxious than the DBA/2 mice. The anxiety score (open arm entries in the elevated plus maze) was significantly correlated with all measures of learning and memory in the object recognition task, and some measures in the passive avoidance and water maze tasks. Analysis of covariance (with open arm entries as a covariate) revealed that some measures on trial 1 of the object recognition task, but not the memory scores on trial 2, were confounded by anxiety. No confounding factors of anxiety were found in the water maze or passive avoidance tasks. Similar results were obtained with the activity scores (line crossing and rearing in the open field). In conclusion, strain differences in activity and anxiety did not account for strain differences in learning and memory performance of C57BL/6 and DBA/2 mice. Nonetheless, the importance of using complete behavioural test batteries should be stressed to ensure that strain differences in learning and memory tasks are not confounded by non-cognitive factors.     

昆明小鼠物体识别模型的建立及其在检测化学药物对记忆损伤中的应用

本研究的主要目的是建立昆明小鼠物体识别模型并评价该模型在安全药理学研究中的潜在应用价值。研究了昆明小鼠物体识别记忆随时间而减弱的特性,在训练结束后4h或1h,检测昆明小鼠的物体识别记忆,并评价了东莨胆碱对昆明小鼠物体识别记忆的影响。结果表明:1h间隔组昆明小鼠熟悉期探究物体的时间差和测试期探究物体的时间差存在显著差异(P<0.05),昆明小鼠在训练结束后1h记忆保持良好,可以进行物体识别;东莨胆碱组昆明小鼠熟悉期探究物体的时间差和测试期探究物体的时间差比较(P>0.05),没有显著性差异。因此,东莨胆碱损伤了昆明小鼠的物体识别记忆。用昆明小鼠建立的物体识别模型具有简单、快速、可靠等特点,在安全药理学研究中可用于检测化学药物对记忆的损伤。     

Correlations of recognition memory performance with expression and methylation of brain-derived neurotrophic factor in rats

Object recognition memory allows discrimination between novel and familiar objects. This kind of memory consists of two components: recollection, which depends on the hippocampus, and familiarity, which depends on the perirhinal cortex (Pcx). The importance of brain-derived neurotrophic factor (BDNF) for recognition memory has already been recognized. Recent evidence suggests that DNA methylation regulates the expression of BDNF and memory. Behavioral and molecular approaches were used to understand the potential contribution of DNA methylation to recognition memory. To that end, rats were tested for their ability to distinguish novel from familiar objects by using a spontaneous object recognition task. Furthermore, the level of DNA methylation was estimated after trials with a methyl-sensitive PCR. We found a significant correlation between performance on the novel object task and the expression of BDNF, negatively in hippocampal slices and positively in perirhinal cortical slices. By contrast, methylation of DNA in CpG island 1 in the promoter of exon 1 in BDNF only correlated in hippocampal slices, but not in the Pxc cortical slices from trained animals. These results suggest that DNA methylation may be involved in the regulation of the BDNF gene during recognition memory, at least in the hippocampus.     

The neurosteroid allopregnanolone impairs object memory and contextual fear memory in male C57BL/6J mice

Allopregnanolone (ALLO, or 3α-hydroxy-5α-pregnan-20-one) is a steroid metabolite of progesterone and a potent endogenous positive allosteric modulator of GABA-A receptors. Systemic ALLO has been reported to impair spatial, but not nonspatial learning in the Morris water maze (MWM) and contextual memory in rodents. These cognitive effects suggest an influence of ALLO on hippocampal-dependent memory, although the specific nature of the neurosteroid's effects on learning, memory or performance is unclear. The present studies aimed to determine: (i) the memory process(es) affected by systemic ALLO using a nonspatial object memory task; and (ii) whether ALLO affects object memory via an influence within the dorsal hippocampus. Male C57BL/6J mice received systemic ALLO either before or immediately after the sample session of a novel object recognition (NOR) task. Results demonstrated that systemic ALLO impaired the encoding and consolidation of object memory. A subsequent study revealed that bilateral microinfusion of ALLO into the CA1 region of dorsal hippocampus immediately following the NOR sample session also impaired object memory consolidation. In light of debate over the hippocampal-dependence of object recognition memory, we also tested systemic ALLO-treated mice on a contextual and cued fear-conditioning task. Systemic ALLO impaired the encoding of contextual memory when administered prior to the context pre-exposure session. Together, these results indicate that ALLO exhibits primary effects on memory encoding and consolidation, and extend previous findings by demonstrating a sensitivity of nonspatial memory to ALLO, likely by disrupting dorsal hippocampal function.     

Spatial interactions in rapid pattern discrimination

We measured reaction times (RTs) for identification of a target among distracters under stabilized image conditions in which the positions of the target and the distracters were constant within a single experimental session. Under these conditions, the observer need not search for the target because its position is known. We nevertheless found that the presence of even a single distracter could elevate RTs. The magnitude of this effect depended on the distance of the distracter from the target and, for some observers, the distance of the distracter from the fovea. When we added not one but six background elements in a ring around the target, RT increased even more. If, apart from these neighboring distracters, the target was surrounded by more distracters located beyond the nearest neighbors, RT was, in general, not increased further. These findings suggest that adding background elements in a search task can elevate RTs in ways that are not dependent on the positional uncertainty of the target.     

Memory and Language in Middle Childhood in Individuals with a History of Specific Language Impairment

This study reports on the sensitivity of sentence repetition as a marker of specific language impairment (SLI) in different subgroups of children in middle childhood and examines the role of memory and grammatical knowledge in the performance of children with and without language difficulties on this task. Eleven year old children, 197 with a history of SLI and 75 typically developing (TD) peers were administered sentence repetition, phonological short term memory (PSTM) and grammatical morphology tasks. Children with a history of SLI were divided into four subgroups: specific language impairment, non-specific language impairment, low cognition with resolved language and resolved. Performance on the sentence repetition task was significantly impaired in all four subgroups of children with a history of SLI when compared to their age peers. Regression analyses revealed grammatical knowledge was predictive of performance for TD children and children with a history of SLI. However, memory abilities were significantly predictive of sentence repetition task performance for children with a history of SLI only. Processes involved in sentence repetition are more taxing of PSTM for individuals with a history of SLI in middle childhood in a way that does not appear to be the case for TD children.     

Does Physical Contact with a Dog or Person Affect Performance of a Working Memory Task?

ABSTRACT

Working memory (WM) plays a critical role in the execution of a wide variety of cognitive tasks and predicts academic success. This study was designed to compare the impact of the presence of a dog or a person, and physical contact with them, on the performance of a WM task. It also exam- ined whether the impact differed for two dogs, and whether these factors im- pacted arousal during the WM task. College students (n=31, aged 18–23 years) performed a WM task in five counterbalanced conditions; dog-touch, dog-no-touch, person-touch, person-no-touch, and alone. Participants were randomly assigned to one of two dogs; Miniature Poodle (n=16) or Border Collie (n=15). The WM task involved replicating increasingly complicated se- quences of colored lights by touching them on an iPad^®. Linear mixed model analyses revealed there was a significant interaction between collaborator and touch (p=0.05); best WM scores occurred without touch with either the per- son or the dog present, and worst WM scores occurred when the participant was touching a dog. Analyzing WM test during the dog conditions, touch (p=0.027) and dog breed (p=0.042) contributed independently to it; task completion was worse when the poodle was present and better without touch. Physiological measures [heart rate (HR) and heart rate variability] during the ex- periment indicated that the WM task was physiologically arousing (p<0.001) compared with listening, and HR was higher when touching a person than a dog during the task (p<0.046). These results are consistent with facilitation of performance by the presence of an observer. If there is a beneficial effect on cognition from a dog, physical contact with the dog might not be a necessary component. Aspects of the dog (e.g., breed) are also likely factors in WM task performance. This study highlights the importance of situational characteristics in studies evaluating the impact of companion animals.     

Formation of spatial short-term memory in 18-54-month old children

The development of the spatial short-term memory (SSTM) in children aged 18-54-months was assessed by performance of the inverted delayed-response task (IDR). A child perceived the localization of a target object in one of the two containers (left or right) situated on a table in front of the child. The distance between the containers was 30 cm. Then the child was escorted to the opposite side of the table so that the target object that was earlier in the left container seemed to be in the right one. After the rotation, in 74% of cases children at the age of 18-24-months failed to localize the object correctly despite the presence of various reference objects in the room. Percent of correct responses increased with age. Children aged 24-54-months performed the IDR better in the presence of reference objects than in their absence. The preschool children at the age of 48-54-months correctly localized the object in 70% of cases even in the absence of the experimental reference objects. The results of this experiment demonstrate the stages of the SSTM development in children.