Context attributes in memory are bound to item information,but not to one another

In four experiments, we compared binding between item and context information with binding between different types of context information. Participants studied line drawings of common objects that appeared in both different colors and different locations. We explored the effects of reinstating one type of information on recognition memory for another type, and we also tested the participants’ ability to discriminate intact from rearranged pairings of two types of information. Results showed that different contextual dimensions (i.e., color and location) were bound to item information (i.e., object information), but not to each other.     

Learning by looking: Infants' social looking behavior across the transition from crawling to walking

This study investigated how infants gather information about their environment through looking and how that changes with increases in motor skills. In Experiment 1, 9.5- and 14-month-olds participated in a 10-min free play session with both a stranger and ambiguous toys present. There was a significant developmental progression from passive to active social engagement, as evidenced by younger infants watching others communicate more and older infants making more bids for social interaction. Experiment 2 examined longitudinally the impact of age and walking onset on this progression. The transition to independent walking marked significant changes in how often infants watched others communicate and made active bids for social interaction. Results suggest that infants transition from passive observers as crawlers to active participants in their social environment with the onset of walking.     

Objects but not concepts modulate the size of the attended region

Here we investigated the types of stimuli that modulate the size of the attentional spotlight. In particular, it has been previously shown that conceptual cues that either directly refer to or are semantically related to particular spatial locations can shift attention to that location (known as “conceptual cueing”). For example, reading the word sun or joy can shift attention upward whereas the word boot or hostile can shift attention downward. Here, therefore, we tested whether words could modulate the size of the attended area. Across five experiments, we found that words that either directly referred to, or were abstractly associated with, particular sizes (small versus large) did not change the size of the attentional spotlight, whereas the presence of differently sized stimuli did, as evidenced by faster responses to targets when the spotlight is small than when it is large. This suggests that physical but not conceptual inducers can modulate the size of the attentional spotlight. This highlights an important difference between the regulation of spotlight size and shifts of attention, supporting the notion that they are subserved by distinct mechanisms.     

Lengthening the duration of response execution does not modulate blindness to action-compatible stimuli.

Action-compatible blindness refers to the finding that target stimuli are perceived less frequently if they are presented during the planning or execution of a compatible action (e.g., a left arrow presented during a left manual key press) than during an incompatible action (Müsseler & Hommel, 1997 a, b). We investigated the effect of lengthening the response execution phase in the action-compatible blindness paradigm by requiring subjects to tap a response key once or three times on the assumption that tapping three times would increase the duration of the execution phase of the response. Prior research (e.g., Stevanovski, Oriet, & Jolicoeur, 2002; Wühr & Müsseler, 2001) has shown that larger blindness effects are observed for targets presented during the execution phase of a response than after the response has been made. We investigated whether a larger blindness effect would be observed in the three-tap condition than in the one-tap condition, or whether lengthening the duration of the response would extend the time course of the blindness effect. Neither of these possibilities was supported by the data irrespective of whether the number of taps to be made was blocked or mixed within a block of trials. The results are discussed in terms of current accounts of action-compatible blindness and the possible cognitive differences between making a single response and repeating a response.     

Semantic interference in language production is due to graded similarity,not response relevance

There is an ongoing debate on the question whether semantic interference effects in language production reflect competitive processes at the level of lexical selection or whether they reflect a post-lexical bottleneck, occupied in particular by response-relevant distractor words. To disentangle item-inherent categorical relatedness and task-related response relevance effects, we combined the picture–word interference task with the conditional naming paradigm in an orthogonal design, varying categorical relatedness and task-related response relevance independent of each other. Participants were instructed to name only objects that are typically seen in or on the water (e.g. canoe) and refrain from naming objects that are typically located outside the water (e.g. bike), and vice versa. Semantic relatedness and the response relevance of superimposed distractor words were manipulated orthogonally. The pattern of results revealed no evidence for response relevance as a major source of semantic interference effects in the PWI paradigm. In contrast, our data demonstrate that semantic similarity beyond categorical relations is critical for interference effects to be observed. Together, these findings provide support for the assumption that lexical selection is competitive and that semantic interference effects in the PWI paradigm reflect this competition.     

Putting action memory to the test: testing affects subsequent restudy but not long-term forgetting of action events

Testing memory typically enhances subsequent re-encoding of information (“indirect” testing effect) and, as compared to restudy, it also benefits later long-term retention (“direct” testing effect). We investigated the effect of testing on subsequent restudy and 1-week retention of action events (e.g. “water the plant”). In addition, we investigated if the type of recall practice (noun-cued vs. verb-cued) moderates these testing benefits. The results showed an indirect testing effect that increased following noun-cued recall of verbs as compared to verb-cued recall of nouns. In contrast, a direct testing effect on the forgetting rate of performed actions was not reliably observed, neither for noun- nor verb-cued recall. Thus, to the extent that this study successfully dissociated direct and indirect testing-based enhancements, they seem to be differentially effective for performed actions, and may rely on partially different mechanisms.     

Production deficiencies in elicited language but not in the spontaneous verbalizations of hyperactive children

Setting and task conditions were assessed for their effects on the language of hyperactive children. Verbal data were recorded for 22 hyperactive children and 22 elementary-age controls during four storytelling tasks and transitions, and under two conditions of a nonverbal performance task in a counterbalanced order. Findings were that hyperactive children were more spontaneously talkative than their classmates during transitions and nonverbal tasks (nonelicited conditions) but were less talkative when they were asked to tell stories (elicited conditions). These findings and those attributable to the story comparisons were interpreted in line with the optimal stimulation theory, which suggests that minimal stimulus input (delays and nonelicited conditions) precipitate excessive verbal activity from hyperactive children. Production deficiencies, on the other hand, were specific to type of stimulus input to be processed. Stories requiring organization and planning without the external structure or salience of visual cues (a sequence of word cards or pictures) produced production deficiencies.I thank Margo Wilson for her expertise in the development and scoring of the language measures. I am also grateful to Mary Kemper for help with data collection, and to Joe Boggs and Connie Hobbs for their assistance with data analyses.     

Selectively ignoring locations does not modulate contingent involuntary orienting,but selectively attending does

Attending to a location in the visual field facilitates processing of objects in that location, and numerous studies have revealed processing benefits by precuing target locations. Recent studies have also demonstrated that precuing a location to ignore reduces distraction by items in that location; however, precuing a feature (colour) to ignore increases distractor interference, at least before a template for rejection is established. Thus, locations, not features, can be selectively ignored. The present study used a spatial cuing task to examine whether featurally-relevant items are selected when they appear in ignored locations. The results revealed contingent attentional capture by target-relevant cues (red cue when searching for red targets, but not for onset targets), even when the cue appeared in a location that was ignored. Importantly, this was equivalent to contingent capture elicited by cues in non-ignored locations. However, when observers were precued to the target location, contingent capture was largely eliminated. The results suggest salient items with target-relevant features are selected from selectively ignored locations, but focusing attention onto a location can preclude capture by salient and target-relevant items.     

Impaired memory retrieval correlates with individual differences in cortisol response but not autonomic response

Stress can enhance or impair memory performance. Both cortisol release and sympathetic nervous system responses have been implicated in these differential effects. Here we investigated how memory retrieval might be affected by stress-induced cortisol release, independently of sympathetic nervous system stress responses. Thirty-two healthy participants (16 women) learned emotionally arousing and neutral words. One hour later, half of the participants underwent a stressor (cold pressor test) and the other half, a control warm water exposure, both followed by a delayed free recall task. The stressed participants were split into those who did (responders, N = 8) and those who did not (nonresponders, N = 6) show a cortisol response. Both responders and nonresponders showed comparable sympathetic nervous system activity (skin conductance level) during the cold pressor. The cortisol responders recalled significantly fewer words compared to nonresponders, and compared to control participants; this effect was most pronounced for moderately arousing words (compared to highly arousing and neutral words). These results suggest that individual differences in cortisol reactivity affect memory retrieval performance, and help to explain the differential effects of stress on memory.     

Object-based allocation of visual attention in response to exogenous, but not endogenous, spatial precues

Two rectangular objects were presented in the visual field, and subjects’ attention was directed to a location on one rectangle by either an endogenous or an exogenous spatial precue. Similar experiments by Egly, Driver, and Rafal (1994) have shown an object-based effect: slower target identification when the target was presented on the uncued object, even when the spatial proximity of the target’s and the cue’s location was controlled. The experiment reported here showed that this object-based effect occurs only for exogenous cues. Considered in the light of other literature on spatial cuing, it seems that attention is influenced by nearby objects when exogenously directed to a location, but it is independent of such objects when endogenously directed to a location.     

The gestures of a gorilla: language acquisition in another pongid

A female lowland gorilla, Koko, has been engaged in an ongoing language program since July 1972 when she was 1 year old. During the first 30 months of training she acquired a vocabulary of 100 words in American Sign Language which she spontaneously combined into meaningful and often novel statements of up to 11 signs in length. The gorilla is using a rapidly expanding vocabulary of signs to express semantic and possibly grammatical relations similar to those expressed by human children in the early stages of language acquisition. Patterns of generalization, gradual increase in mean length of utterance, and innovative use of gestural language are discussed in relation to data available on children and chimpanzees.     

Infants of chronically depressed mothers learn in response to male, but not female, infant-directed speech

Previous research using a conditioned-attention paradigm demonstrated that 4-month-old infants of depressed mothers (a) failed to acquire associations when a segment of their mothers' infant-directed (ID) speech signaled the presentation of a smiling face but (b) did acquire associations when a segment of an unfamiliar nondepressed mother's ID speech signaled the face (P. S. Kaplan, J. -A. Bachorowski, M. J. Smoski, & W. J. Hudenko, 2002). In the present study, 5- to 13-month-old infants of depressed mothers failed to acquire associations when either their own mothers' (Experiment 1) or an unfamiliar nondepressed mother's (Experiments 1 and 2) ID speech signaled a face. However, these infants acquired associations when a segment of an unfamiliar nondepressed father's ID speech served as the signal (Experiment 2). One possible explanation of these results is that infants of depressed mothers selectively "tune out" ID speech from their mothers and from other, nondepressed, women.     

Born to adapt, but not in your dreams

The brain adapts to changes that take place in the body. Deprivation of input results in size reduction of cortical representations, whereas an increase in input results in an increase of representational space. Amputation forms one of the most dramatic disturbances of the integrity of the body. The brain adapts in many ways to this breakdown of the afferent–efferent equilibrium. However, almost all studies focus on the sensorimotor consequences. It is not known whether adaptation takes place also at other “levels” in the system. The present study addresses the question whether amputees dream about their intact body, as before the amputation, or about the body after the amputation and whether the dream content was a function of time since the amputation and type of amputation. The results show that the majority of the dreamers reported dreams about their intact body although the mean time that elapsed since the amputation was twelve years. There is no clear relation with the type of amputation. The results give modest evidence for the existence of a basic neural representation of the body that is, at least, partly genetically determined and by this relatively insensitive for changes in the sensory input.     

Basolateral amygdala inactivation impairs learned (but not innate) fear response in rats

Numerous studies have suggested that the amygdala is involved in the formation of aversive memories, but the possibility that this structure is merely related to any kind of fear sensation or response could not be ruled out in previous studies. The present study investigated the effects of bilateral inactivation of the amygdaloid complex in rats tested in the plus-maze discriminative avoidance task. This task concomitantly evaluates aversive memory (by discrimination of the two enclosed arms) and innate fear (by open-arm exploration). Wistar rats (3-5 months-old) were implanted with bilateral guide cannulae into basolateral amygdala. After surgery, all subjects were given 1 week to recover before behavioral experiments. Afterwards, in experiment 1, 15 min prior to training, 0.5 μl of saline or muscimol (1 mg/ml) was infused in each side via microinjection needles. In experiment 2 the animals received injections immediately after the training session and in experiment 3 rats were injected prior to testing session (24 h after training). The main results showed that (1) pre-training muscimol prevented memory retention (evaluated by aversive arm exploration in the test session), but did not alter innate fear (evaluated by percent time in open arms); (2) post-training muscimol impaired consolidation, inducing increased percent in aversive arm exploration in the test session and (3) pre-testing muscimol did not affect retrieval (evaluated by aversive enclosed arm exploration in the test session). The results suggest that amygdala inactivation specifically modulated the learning of the aversive task, excluding a possible secondary effect of amygdala inactivation on general fear responses. Additionally, our data corroborate the hypothesis that basolateral amygdala is not the specific site of storage of aversive memories, since retention of the previously learned task was not affected by pre-testing inactivation.     

Attachment style predicts cooperation in intuitive but not deliberative response in one-shot public goods game

Cooperation is an important prosocial behaviour that is of great significance to individuals and society. The social heuristics hypothesis (SHH) systematically explains how cooperation is interactively affected by intuitive and deliberative processes. On the one hand, the intuitive process can be either cooperative or selfish, which is determined by previous experience. On the other hand, the deliberative process could support either a cooperative decision or a selfish decision, depending on which strategy could maximise the current payoff. This research aims to investigate the mechanism of cooperation. Attachment style was selected as a proxy for previous experience to examine whether and how previous life experience shapes intuitive response. Time constraint (Studies 1 and 2) and cognitive load (Study 3) were manipulated to dissociate the intuitive and deliberative processes. In addition, cooperation was assessed by adopting one-shot public goods games. Results showed that attachment avoidance (Studies 1, 2, and 3) and attachment anxiety (Study 3) significantly predicted cooperation in the intuition condition, whereas these associations were insignificant in the deliberation condition (Studies 1, 2, and 3). These findings provide further support for the SHH and shed new light on the mechanism of cooperation.     

Decision-making and the framing effect in a foreign and native language

Recent research using scenarios such as the Asian disease problem has demonstrated a “foreign-language effect”, whereby the framing effect (tendency to be risk-averse in a gain frame and risk seeking in a loss frame) is not (or not as) apparent in the foreign language as the native language. The aim of the current study was to further investigate decision-making and the framing effect in a native language, Thai and a foreign language, English, using the Asian disease/Financial crisis problem (Study 1) and a novel financial decision-making task (Study 2). Results from Study 1 confirmed previous findings as a foreign-language effect emerged. In contrast, in Study 2, a framing effect emerged in both the native and foreign languages of the Thai participants. These contradictory results point to language factors as well as emotional and cognitive demands of the task contributing to the occurrence of the foreign-language effect.     

Happy babies,chatty toddlers: Infant positive affect facilitates early expressive,but not receptive language

Eighty-three mother–infant dyads participated in this study. Positive affect (PA) broadly, along with fine-grained aspects of PA, was measured at 10 months of age. Language was measured at 14 months. Infant PA predicted expressive, but not receptive, language. The implications of these findings are discussed.