Verbal, visual, and spatial working memory in written language production

College students wrote definitions of either abstract or concrete nouns in longhand while performing a concurrent working memory (WM) task. They detected either a verbal (syllable), visual (shape), or spatial (location) stimulus and decided whether it matched the last one presented 15-45s earlier. Writing definitions of both noun types elevated the response time to verbal targets above baseline. Such interference was observed for visual targets only when defining concrete nouns and was eliminated entirely with spatial targets. The interference effect for verbal targets was the same whether they were read or heard, implicating phonological storage. The findings suggest that language production requires phonological or verbal WM. Visual WM is selectively engaged when imaging the referents of concrete nouns.     

Stereotype content of people with acquired brain injury: Warm but incompetent

Since stereotypes about people with acquired brain injury (ABI) can lead to prejudice, studying these stereotypes is highly important. In two studies, we examined these stereotypes both on idiosyncratic dimensions and on the two dimensions of the Stereotype Content Model. Participants completed a specific questionnaire about ABI and warmth and competence questionnaires regarding people with ABI and other social groups. Specific stereotypes about ABI were found to be underpinned by dimensions of “cognitive impairments and ADL limitations,” “catastrophic outcomes,” and “personal and interpersonal development.” Within the model, people with ABI were seen as being warm but incompetent. The ambivalent ABI stereotype could elicit prejudicial attitudes that may impede rehabilitation.     

Metamemory following childhood brain injury: A consequence of executive impairment

In this study, we investigated the influence of children’s level of executive functioning on two types of metamemory knowledge following a traumatic brain injury (TBI). For this purpose, 22 children (aged 7 to 14 years) who had sustained a moderate to severe TBI and 44 typically developing children were recruited. The children with TBI were divided into two groups according to the severity of their executive impairment. Injury severity was determined by the Glasgow Coma Scale (GCS) score on admission or by the duration of unconsciousness. All children were then tested on both their knowledge of general memory functioning and their level of memory self-awareness, respectively assessed using the total number of correct responses on an adapted version of a metamemory interview and a self-other discrepancy score on a questionnaire evaluating everyday memory abilities. Data analyses revealed that participants with TBI who suffered impaired executive functions demonstrated less general metamemory knowledge, and underestimated the frequency of their memory problems, compared with children with TBI who had preserved executive functions and with control participants. Considering the well-established effect of metamemory knowledge on people’s spontaneous implementation of strategies, the interest and the importance of these findings on both theoretical and clinical grounds are discussed.     

Suppression of attentional bias in PTSD

Sixty combat veterans with posttraumatic stress disorder performed an emotional Stroop task under 1 of 4 contextual conditions designed to test theoretical explanations for an attentional bias suppression effect. Results revealed that when the emotional Stroop task was performed under conditions involving a future threat of either watching a combat video or giving a speech, attentional bias was inhibited. There was limited support for the prediction that the suppression effect was strongest when stressor content matched word content on the Stroop. In contrast to participants in the threat conditions, veterans who believed that they would receive additional compensation for speeded color naming or who believed that they would have no other experimental demands were slower when color naming combat-threat words. Potential theoretical explanations of the findings are discussed.     

Following and joining the informed individual in semifree-ranging tonkean macaques (Macaca tonkeana)

The authors investigated whether Tonkean macaques (Macaca tonkeana) can distinguish between 2 group mates with different knowledge and improve their foraging performance. The subjects were 8 young individuals belonging to a group raised in a 2-acre park. The authors carried out 192 tests in which subgroups of 3 individuals were released in a food search situation. Two leaders could be informed about 2 different food sites. A naive follower could choose to follow 1 leader or another. The follower could find the correct site when 1 leader was informed about food location. There was no evidence that the follower identified the best leader, however. The less well-informed leader generally joined the other leader, prompting the follower to follow them. The followers' pathways were mainly determined by the interactions of leaders.     

Implicit learning of complex information in amnesia

Implicit learning abilities of nine amnesic patients were explored by using an artificial grammar learning task in which the test strings were constructed in such a way that grammaticality judgments could not be based on a simple knowledge of bigrams and trigrams (chunks). Results show that amnesic patients and controls performed at the same level during the classification task, whereas amnesic patients performed worse than controls in an explicit generation task. Moreover, there was no correlation between the implicit and explicit measures. These results are compatible with the existence of two kinds of representation intervening in artificial grammar learning. The first one based on processes leading to fragment-specific knowledge (the chunks, which can be accessed explicitly), and the second based on the learning of simple associations and more complex conditional relations between elements.     

Sequential compatibility effects and cognitive control: does conflict really matter?

Although it is widely accepted that control mechanisms are necessary for human behavior to be adapted, very little is known about how such mechanisms are recruited. A suggestion to fill the gap was put forward by M. M. Botvinick, T. S. Braver, C. S. Carter, D. M. Barch, and J. D. Cohen (2001), who proposed the conflict-loop theory. This theory has been successful in accounting for the reduction of compatibility effects after an incompatible trial: The level of conflict being, on average, higher during an incompatible trial, more control occurs after such a trial. The authors have tested this prediction by sorting the trials on the basis of amount of conflict (quantified by the electromyographic activity) they presented. A reduction of the compatibility effect was observed after incompatible trials, but it was independent of the level of conflict on previous trials, suggesting that the conflict does not trigger changes in executive control. Consequences for the conflict monitoring model are discussed.     

Partial advance information,number of alternatives,and motor processes: an electromyographic study

We present evidence that advance information reducing the number of stimulus-response alternatives in a choice reaction time (RT) task can shorten the very latest motoric stages of RT. Effects of such advance information on late stages of RT have been demonstrated recently by Osman, Moore, and Ulrich (Acta Psychol. 90 (1995) 111), Leuthold, Sommer, and Ulrich (J. Exp. Psychol: Gen. 125 (1996) 307), Müller-Gethmann, Rinkenauer, Stahl, and Ulrich (Psychophysiology 37 (2000) 507). These studies found that advance information shortens the portion of the RT interval following onset of a movement-related brain potential (lateralized readiness potential). Osman et al. and Müller-Gethmann et al. also examined the portion of the RT interval following the start of electromyographic (EMG) activity and found no effect of advance information. Based on Osman et al.'s null result, Leuthold et al. speculated that advance information may shorten only the RT stages preceding EMG activity. This conclusion, however, is questionable because of limitations in the EMG measures employed by both Osman et al. and Müller-Gethmann et al. We have reanalyzed the results of a previously reported experiment (Acta Psychol. 101 (1999) 243) to show that advance information can in fact affect the rate of recruitment of motor units in the prime mover of the responding limb.     

Call me Alix,not Elix: vowels are more important than consonants in own‐name recognition at 5 months

Consonants and vowels differ acoustically and articulatorily, but also functionally: Consonants are more relevant for lexical processing, and vowels for prosodic/syntactic processing. These functional biases could be powerful bootstrapping mechanisms for learning language, but their developmental origin remains unclear. The relative importance of consonants and vowels at the onset of lexical acquisition was assessed in French‐learning 5‐month‐olds by testing sensitivity to minimal phonetic changes in their own name. Infants’ reactions to mispronunciations revealed sensitivity to vowel but not consonant changes. Vowels were also more salient (on duration and intensity) but less distinct (on spectrally based measures) than consonants. Lastly, vowel (but not consonant) mispronunciation detection was modulated by acoustic factors, in particular spectrally based distance. These results establish that consonant changes do not affect lexical recognition at 5 months, while vowel changes do; the consonant bias observed later in development does not emerge until after 5 months through additional language exposure.     

Time’s up! Involvement of metamemory knowledge,executive functions,and time monitoring in children’s prospective memory performance

This study examined time-based prospective memory (PM) in children and explored the possible involvement of metamemory knowledge and executive functions in the use of an appropriate time-monitoring strategy depending on the ongoing task’s difficulty. Specifically, a sample of 72 typically developing children aged 4, 6, and 9 years old were given an original PM paradigm composed of both an ongoing procedural activity and a PM task. Half of the participants (expert group) were trained in the ongoing activity before the prospective test. As expected, results show that time monitoring had a positive effect on children’s PM performance. Furthermore, mediation analyses reveal that strategic time monitoring was predicted by metamemory knowledge in the expert group but only by executive functions in the novice group. Overall, these findings provide interesting avenues to explain how metamemory knowledge, strategy use, and executive functions interact to improve PM performance during childhood.