Dogs are able to solve a means-end task

Dogs, although very skilled in social-communicative tasks, have shown limited abilities in the domain of physical cognition. Consequently, several researchers hypothesized that domestication enhanced dogs’ cognitive abilities in the social realm, but relaxed selection on the physical one. For instance, dogs failed to demonstrate means-end understanding, an important form of relying on physical causal connection, when tested in a string-pulling task. Here, we tested dogs in an “on/off” task using a novel approach. Thirty-two dogs were confronted with four different conditions in which they could choose between two boards one with a reward “on” and another one with a reward “off” (reward was placed next to the board). The dogs chose the correct board when (1) both rewards were placed at the same distance from the dog, when (2) the reward placed “on” the board was closer to the dog, and (3) even when the reward placed “off” the board was much closer to the dog and was food. Interestingly, in the latter case, dogs did not perform above chance, if instead of a direct reward, the dogs had to retrieve an object placed on the board to get a food reward. In contrast to previous string-pulling studies, our results show that dogs are able to solve a means-end task even if proximity of the unsupported reward is a confounding factor.     

Tone of voice guides word learning in informative referential contexts

Listeners infer which object in a visual scene a speaker refers to from the systematic variation of the speaker's tone of voice (ToV). We examined whether ToV also guides word learning. During exposure, participants heard novel adjectives (e.g., “daxen”) spoken with a ToV representing hot, cold, strong, weak, big, or small while viewing picture pairs representing the meaning of the adjective and its antonym (e.g., elephant–ant for big–small). Eye fixations were recorded to monitor referent detection and learning. During test, participants heard the adjectives spoken with a neutral ToV, while selecting referents from familiar and unfamiliar picture pairs. Participants were able to learn the adjectives' meanings, and, even in the absence of informative ToV, generalize them to new referents. A second experiment addressed whether ToV provides sufficient information to infer the adjectival meaning or needs to operate within a referential context providing information about the relevant semantic dimension. Participants who saw printed versions of the novel words during exposure performed at chance during test. ToV, in conjunction with the referential context, thus serves as a cue to word meaning. ToV establishes relations between labels and referents for listeners to exploit in word learning.     

Task constraints mask great apes' ability to solve the trap-table task

Researchers have investigated animals' causal knowledge with a task requiring subjects to use a tool to bring a reward within reach whilst avoiding a trap. Previous studies have suggested limitations in the ability of several species to avoid traps in tubes or tables. However, certain features may have inflated task difficulty. We tested 20 chimpanzees (Pan troglodytes), 7 orangutans (Pongo pygmaeus), 5 bonobos (Pan paniscus), and 5 gorillas (Gorilla gorilla) in the trap-table--a task in which subjects have to pull one of two rakes prepositioned behind two rewards on a flat surface. One of the rewards is in front of a trap into which it will fall. We investigated the effect of trap type, tool type, the number of available tools, and reinforcement regime on performance. We replicated previous findings showing that apes failed to choose the correct rake above chance. However, when they could instead choose where to insert a single tool, around 80% of the apes solved the trap-table task in the first trial, revealing an important effect of task constraints on their performance.     

Mechanisms of blocking by contextual stimuli

The influence of contextual stimuli on the conditioning and performance of responding to a discrete stimulus was examined in the US preexposure paradigm using both context shift manipulations and a measure of context conditioning. Four groups of rats received both repeated exposure to an electric shock US in one context (Context 1), and repeated nonshocked exposure to a second context (Context 2). Two additional groups of rats received exposure to these contexts, but never received shock presentations. Rats exposed to shock learned to escape from the stimuli of Context 1, but did not escape from the stimuli provided by Context 2. Rats not exposed to shock failed to escape from either context. All rats then received a single CER conditioning session in which four pairings of a 3-min noise CS and shock US were presented. Half the rats received those CS-US pairings in the excitatory Context 1, while the remaining rats received those pairings in the neutral Context 2. Finally, half the rats in each of the CER conditioning treatments received extinction test trials of the noise CS in Context 1, while the remaining rats received those test trials in Context 2. Thus, this design factorially manipulated the presence of excitatory or neutral contextual stimuli during both conditioning and testing of a discrete CS. In comparison with the two groups of rats never preexposed to shock alone, attenuation in acquisition of conditioned suppression observed during test trials occurred only when CER conditioning had been administered in the excitatory Context 1, and this effect was manifested when testing occurred in either the excitatory Context 1 or the neutral Context 2. These results support the model of R. A. Rescorla and A. R. Wagner (1972) (in A. H. Black & W. F. Prokasy (Eds.) Classical Conditioning II, pp. 64–99, New York: Appleton-Century-Crofts) which asserts that contextual stimuli and sicrete CSs compete for limited associative strength supportable by a given US.     

There goes the neighbourhood: contextual control over the breadth of lexical activation when reading aloud

There are currently two computational accounts of how the time to read pseudohomophones (like BRANE) and their nonword controls (like FRANE) varies with changes in context. In Reynolds and Besner's (2005) account, readers vary the breadth of lexical activation in response to changes in context. A competing account proposed by Kwantes and Marmurek (2007) and independently by Perry, Ziegler, and Zorzi (2007) has readers varying their response criterion in response to changes in context. The present work adjudicates between these two accounts by examining how the effect of neighbourhood density changes as a function of list context when reading pseudohomophones aloud. The results of an experiment and simulations from a leading computational model support the lexical breadth account, but are inconsistent with the response criterion account.     

REM restriction persistently alters strategy used to solve a spatial task

We tested the hypothesis that rapid eye movement (REM) sleep is important for complex associative learning by restricting rats from entering REM sleep for 4 h either immediately after training on an eight-box spatial task (0-4 REMr) or 4 h following training (4-8 REMr). Both groups of REM-restricted rats eventually reached the same overall performance level as did nonrestricted controls, but 0-4 REMr animals were delayed in their improvement in the first few days and lagged behind controls in the middle portion of the training period. More importantly, performance gains of 0-4 REMr rats depended more on simple local cues throughout the 15-d study since, unlike control and 4-8 REMr animals, their error rate increased after daily disruption of the relationship between local (intramaze) cues and the food reward. Thus, although overall performance was only subtly and transiently impaired, due to the ability to use alternate, nonspatial behavioral strategies, complex associative (spatial) learning was persistently impaired by restricting REM for a short critical period each day.     

State anxiety impairs attentional control when other sources of control are minimal

Research suggests anxiety impairs attentional control; however, this effect has been unreliable. We argue that anxiety’s impairment of attentional control is subtle, and can be obscured by other non-emotional sources of control. We demonstrate this by examining conflict adaptation, an enhancement in attentional control following a trial with high conflict between distracter and target stimuli. Participants completed a Stroop task featuring incongruent (e.g. RED in green font; high-conflict) and control (e.g. +++ in green font; low-conflict) trials. More state-anxious participants showed greater Stroop interference following control trials, but interference was uniformly low following incongruent trials. This suggests state anxiety can impair attention, but other sources of top-down control – such as conflict adaptation – can easily overcome this impairment. This is consistent with recent theories of anxious cognition and shows that anxiety researchers must attend to the dynamics and sources of attentional control.     

Electrophysiological evidence for greater attention to threat when cognitive control resources are depleted

In this study, we investigated the time course of attentional bias for threat-related (angry) facial expressions under conditions of high versus low cognitive (working memory) load. Event-related potential (ERP) and reaction time (RT) data were recorded while participants viewed pairs of faces (angry paired with neutral face) displayed for 500 ms and followed by a probe. Participants were required to respond to the probe while performing a concurrent task of holding in working memory a sequence of digits that were either in the same order (low memory load) or in a random mixed order (high memory load). The ERP results revealed that higher working memory load resulted in enhanced lateralized neural responses to threatening relative to neutral faces, consistent with greater initial orienting of attention to threatening faces (early N2pc: 180–252 ms) and enhanced maintenance of processing representations of threat (late N2pc, 252–320 ms; SPCN, 320–500 ms). The ERP indices showed significant positive relationships with each other, and also with the behavioral index of attentional bias to threat (reflected by faster RTs to probes replacing angry than neutral faces at 500 ms), although the latter index was not significantly influenced by memory load. Overall, the findings indicate that depletion of cognitive control resources, using a working memory manipulation, increases the capacity of task-irrelevant threat cues to capture and hold attention.     

Concrete problems in the abstract deontic selection task - and how to solve them

The abstract deontic selection task was introduced by Cheng and Holyoak with the aim of demonstrating that people possess abstract reasoning schemas for processing deontic rules about what an individual must, must not, may, or need not do. Solving this task requires people to detect possible rule violators. The average solution rate across several studies, while being substantially higher than that with abstract nondeontic tasks, did not reach the level obtained with concrete deontic tasks. A task analysis based on the deontic principles by Beller uncovers several problems with the formulation of the original task. They concern the presentation of the deontic rule as well as the instructions (focusing on rule following) and result in a specific selection behaviour. Three experiments replicate the difficulties with the original task and show that task performance increases when the formulation problems are resolved. The best performance was obtained with a task that combined a genuine violation detection instruction with a genuine permission rule. Interestingly, permissions are weak deontic rules that, if taken literally, cannot be violated in a deontic sense. Therefore, people must interpret these rules as implying a strong deontic constraint (i.e., a ban), which then constitutes the basis for solving the task. The results provide novel insights into the interpretation of deontic rules and into the role that these content-specific, but abstract, tasks can play for the study of reasoning processes.     

Effects of task performance and contextual performance on systemic rewards

Evidence from 2 samples of Air Force mechanics supported the hypothesis that contextual performance affects employees' career advancement and rewards over time. Results of hierarchical regressions controlling for experience showed task performance and contextual performance each predicted systemic rewards. Each facet explained separate variance in promotability ratings over 2 years. In both samples, contextual performance explained separate variance in informal rewards but task performance did not. Task performance explained incremental variance in career advancement 1 year later but contextual performance did not. Analyses using correlations corrected for unreliability suggest these results cannot be attributed to measurement error. Contextual performance still explained separate variance in informal rewards, and task performance explained distinct variance in career advancement a year later.     

The relative importance of task and contextual performance dimensions to supervisor judgments of overall performance

Although evidence supports the unique contribution of task performance and contextual performance to overall evaluations, little is known about the relative contribution that specific dimensions of contextual performance make to overall performance judgments. This study evaluated the extent to which supervisors consider task and contextual performance by using relative weights (J. W. Johnson, 2000) to statistically describe the relative importance of specific dimensions of each type of performance to overall performance ratings. Within each of 8 job families in a large organization, each of 4 dimensions of contextual performance made not only a unique contribution but a relatively important contribution to the overall evaluation. Evidence also supports the adaptive performance dimension of handling work stress as an aspect of contextual performance and job-task conscientiousness as an aspect of both task and contextual performance.     

On the inability to ignore touch when responding to vision in the crossmodal congruency task

We investigated the extent to which people can selectively ignore distracting vibrotactile information when performing a visual task. In Experiment 1, participants made speeded elevation discrimination responses (up vs. down) to a series of visual targets presented from one of two eccentricities on either side of central fixation, while simultaneously trying to ignore task-irrelevant vibrotactile distractors presented independently to the finger (up) vs. thumb (down) of either hand. Participants responded significantly more slowly, and somewhat less accurately, when the elevation of the vibrotactile distractor was incongruent with that of the visual target than when they were presented from the same (i.e., congruent) elevation. This crossmodal congruency effect was significantly larger when the visual and tactile stimuli appeared on the same side of space than when they appeared on different sides, although the relative eccentricity of the two stimuli within the hemifield (i.e., same vs. different) had little effect on performance. In Experiment 2, participants who crossed their hands over the midline showed a very different pattern of crossmodal congruency effects to participants who adopted an uncrossed hands posture. Our results suggest that both the relative external location and the initial hemispheric projection of the target and distractor stimuli contribute jointly to determining the magnitude of the crossmodal congruency effect when participants have to respond to vision and ignore touch.     

A noted on the relationship between task requirements and the contextual interference effect

Typically, tasks used in past contextual interference experiments had movement, spatial pattern, or timing requirements. The possibility exists that the blocked/random manipulation of only one of these task characteristics contributes to the contextual interference effect. The purpose of the experiment reported here was to test the impact of separate movement and timing tasks on the superior learning of random trained groups. The task for all subjects in the movement condition was to release a start button and knock over a wooden barrier. There were three movement goals to be learned. Half of the subjects in this condition practiced the three movements in a blocked schedule and half practiced them in a random schedule. The subjects in the no-movement condition estimated the same three times by holding down the start button for the appropriate duration. Similarly, these subjects were divided into random and blocked practice groups. All subjects then performed a retention test. Results showed that for the movement condition, the blocked group performed with less error than the random group during acquisition. In retention, however, the random group performed with less error than the blocked group. conversely, for the no-movement condition, there were no differences between the two practice schedule groups during acquisition or during retention for any of the dependent measures. These results indicated that experimental tasks must have some type of movement requirement in order to facilitate learning through the use of random practice schedules.     

Llamas use social information from conspecifics and humans to solve a spatial detour task

Animal Cognition - Learning by observing others (i.e. social learning) is an important mechanism to reduce the costs of individual learning. Social learning can occur between conspecifics but also...     

Hippocampal differentiation without recognition: an fMRI analysis of the contextual cueing task

A central role of the hippocampus is to consolidate conscious forms of learning and memory, while performance on implicit tasks appears to depend upon other structures. Recently, considerable debate has emerged about whether hippocampal-dependent tasks necessarily entail task awareness. In the contextual cueing task, repetition facilitation is implicit, but impaired in patients with amnesia. Whether the hippocampus alone or other MTL structures are required is unclear. Event-related functional magnetic resonance imaging revealed hippocampal activity that differentiates novel from repeated arrays. This pattern of results was observed without recognition of the repeating arrays. This finding provides support for the claim that the hippocampus is involved in processes outside the domain of conscious learning and memory.     

Linking inhibition to activation in the control of task sequences

Inhibition of abandoned tasks in task switching can be inferred when a worse performance is found withn− 2 task repetitions (ABA sequences) than with nonrepetitions (CBA sequences). Recent evidence has shown that this inhibition effect decreases with long intertrial intervals (i.e., response-cue intervals, RCIs). Two alternatives have been proposed to account for this decrease. One alternative attributes the observed decrease to the decay of inhibition itself. The other alternative proposes that decay of the activation of competing tasks reduces the interference and leads to less inhibition. To decide between these alternatives, we manipulated RCI trialwise. The results favor the decay-of-activation account as an explanation for the decreased inhibition effect. This links the amount of inhibition to the activation level of the competing tasks, whereas evidence for the decay of inhibition remains weak.     

The notion of contextual locking: Previously learnt items are not accessible as such when appearing in a less common context

We examined the effect of context on the learning of spatial coding in four experiments. Two partially overlapping sets of stimuli, which had the very same stimulus–response spatial coding, were presented in unique contexts. Results show contextual locking—that is, response times to the very same item in a more common context (80%) were significantly shorter than those in a less common context (20%). Contextual locking was obtained both when the context was more salient (Experiments 1 and 2) and less salient (Experiments 3 and 4). In addition, results were obtained even when contextualization seemed less necessary (Experiments 2 and 4). Binding of information to context is discussed in relation to chunking, transfer effects, and practical applications pertaining to professional training.     

Evaluative conditioning effects are modulated by the nature of contextual pairings

Across two studies participants completed a learning phase comprised of two types of trials: context pairing trials in which two (valenced or non-valenced) words were identical or opposite to one another and evaluative conditioning (EC) trials in which a CS was paired with a US. Based on the idea that EC occurs because CS-US pairings function as a symbolic cue about the relation between the CS and the US, we hypothesised that the nature of context pairings (identical or opposite) might moderate EC effects. Results indicate that identity-based context pairs led to typical assimilative explicit and implicit effects whereas opposition-based pairs led to attenuated effects. Implications and different accounts of our findings are discussed.