Positional information in short-term memory: Relative or absolute?

Evidence suggests that short-term memory for serial order includes information about the positions of items in a sequence. This information is necessary to explain why substitution errors between sequences tend to maintain their position within a sequence. Previous demonstrations of such errors, however, have always used sequences of equal length. With sequences of different length, both transpositions between groups (Experiment 1) and intrusions between trials (Experiment 2) are shown to respect position relative to the end as well as to the start of a sequence. These results support models in which position is coded by start and end markers, but not models in which position is coded in temporal or absolute terms. Possible interpretations of an end marker are discussed.     

How big is big? Relative and absolute properties in memory

Previous studies of semantic memory have overlooked an important distinction among so-called “property statements”. Statements with relative adjectives (e.g., Flamingos are big) imply a comparison to a standard or reference point associated with an immediate superordinate category (a flamingo is big for a bird), while the truth of statements with absolute adjectives (e.g., Flamingos are pink) is generally independent of such a standard. To examine the psychological consequences of this distinction, we asked subjects in Experiment 1 to verify sentences containing either relative or absolute adjectives embedded in either predicate-adjective (PA) constructions (e.g., A flamingo is big (pink)) or predicate-noun (PN) constructions (e.g. A flamingo is a big (pink) bird), where the predicate noun was the immediate superordinate. Reaction times (RTs) and errors for relative sentences decreased when the superordinate was specified, but remained constant for absolute sentences. These data also suggest that the truth value of relative sentences depends, not just on the superordinate, but also on a more global standard for everyday, human-oriented objects. Experiment 2 extends these results in showing that ratings of the truth of relative sentences are a function of the difference in size between an instance and its superordinate standard (e.g., between the size of a flamingo and that of an average bird) and the difference between the instance and the standard for everyday objects. Experiment 3 replicated these findings using reaction time as the dependent measure.     

The mental representation of numerical fractions: real or integer?

Numerical fractions are commonly used to express ratios and proportions (i.e., real numbers), but little is known about how they are mentally represented and processed by skilled adults. Four experiments employed comparison tasks to investigate the distance effect and the effect of the spatial numerical association of response codes (SNARC) for fractions. Results showed that fractions were processed componentially and that the real numerical value of the fraction was not accessed, indicating that processing the fraction's magnitude is not automatic. In contrast, responses were influenced by the numerical magnitude of the components and reflected the simple comparison between numerators, denominators, and reference, depending on the strategy adopted. Strategies were used even by highly skilled participants and were flexibly adapted to the specific experimental context. In line with results on the whole number bias in children, these findings suggest that the understanding of fractions is rooted in the ability to represent discrete numerosities (i.e., integers) rather than real numbers and that the well-known difficulties of children in mastering fractions are circumvented by skilled adults through a flexible use of strategies based on the integer components.     

Can theories of visual representation help to explain asymmetries in amygdala function?

Emotional processing differs between the left and right hemispheres of the brain, and functional differences have been reported more specifically between the left and right amygdalae, subcortical structures heavily implicated in emotional processing. However, the empirical pattern of amygdalar asymmetries is inconsistent with extant theories of emotional asymmetries. Here we review this discrepancy, and we hypothesize that hemispheric differences in visual object processing help to explain the previously reported functional differences between the left and right amygdalae. The implication that perceptual factors play a large role in determining amygdalar asymmetries may help to explain amygdalar dysfunction in the development and maintenance of posttraumatic stress disorder.     

Subtractive versus Ratio Model of “Fair” Allocation: Can the Group Level Analyses Be Misleading?

Two models of equity judgments are ratio and subtraction. Proponents of the former assume a linear relationship between the subjective feelings of equity and their overt expressions; those of the latter assume a monotonic relationship. Consequently, the ratio and subtractive rules are tested with the raw and monotonically rescaled data, respectively. I evaluated these two approaches with managers and students from India. Experiment 1 varied merit and pay of two persons and obtained judgments of difference between unfairness to them. Experiments 2 and 3 manipulated two inputs of two persons and studied “fair” reward for them. I analyzed both the raw and rescaled data at the group and individual levels. The group analyses supported the ratio model; the individual analyses showed that majority was consistent with the subtractive model. Discrepant results from these analyses were due to individual differences in the models employed and use of the response scale. Implications of the findings are discussed for cross-cultural and developmental research in “fair” allocation.     

Response mode differences in perspective taking: Differences in representation or differences in retrieval?

Three experiments explored whether response mode differences in perspective taking result from different spatial representations or different retrieval processes. Participants learned object locations and then, while blindfolded, pointed to or verbally described object locations from perspectives aligned or misaligned with their facing direction and aligned or misaligned with the learning perspective. Pointing was facilitated from the perspective aligned with the body during testing. Similar facilitation occurred when verbally labeling, but only when conducted in the context of pointing (e.g., after pointing). Without this pointing context, or after third-person strategy instructions, the effect of body alignment was eliminated for verbal responses. Pointing was less responsive to context and strategy. Across all conditions, performance was facilitated for the learning perspective. Taken together, these experiments indicate that response mode differences are due to differences in the retrieval process, which varies with strategy, rather than differences in the organization of the underlying spatial memory.     

Finger gnosia: a predictor of numerical abilities in children?

This paper aimed to test the specificity of predicting power of finger gnosia on later numerical abilities in school-age children and to contribute to the understanding of this effect. Forty-one children were tested in the beginning of Grade 1 on finger gnosia, left–right orientation (another sign of the Gerstmann “syndrome”), and global development. Fifteen months later, numerical and reading abilities were assessed. Analyses of the results indicated that, contrary to the general measures of cognitive development, performance in the finger gnosia test was a good predictor of numerical skills 1 year later but not of reading skills, which proves the specificity of that predictor. The same conclusion was also true for the left–right orientation. However, finger gnosia could equally predict performance in numerical tasks that do or do not rely heavily on finger representation or on magnitude representation. Results are discussed in terms of the localizationist and the functional hypotheses.     

Mechanistic versus phenomenal embodiment: Can robot embodiment lead to strong AI?

Embodiment has become the raison d’etre for much of the new ‘cognitive robotics’. It fills a gap in the non-interactivist approach of traditional artificial intelligence (AI) in which ‘intelligence’ is viewed as the manipulation of symbols in a vacuum. However, a foundational question for the new AI is, can embodiment lead to a strong AI, i.e. a robot mind? To address this question, two extreme poles of embodiment are distinguished here, mechanistic and phenomenal. A detailed exploration of each type of embodiment is provided together with an appraisal of whether strong embodiment is possible for robotics, or whether robotics merely provides a tool for scientific exploration and modelling, i.e. weak embodiment? It is argued that strong embodiment, either mechanistic or phenomenal, is not possible for present day robots. However, weak embodiment may provide an enlightened approach to using robots for modelling cognition.     

Finger gnosia: a predictor of numerical abilities in children?

This paper aimed to test the specificity of predicting power of finger gnosia on later numerical abilities in school-age children and to contribute to the understanding of this effect. Forty-one children were tested in the beginning of Grade 1 on finger gnosia, left-right orientation (another sign of the Gerstmann "syndrome"), and global development. Fifteen months later, numerical and reading abilities were assessed. Analyses of the results indicated that, contrary to the general measures of cognitive development, performance in the finger gnosia test was a good predictor of numerical skills 1 year later but not of reading skills, which proves the specificity of that predictor. The same conclusion was also true for the left-right orientation. However, finger gnosia could equally predict performance in numerical tasks that do or do not rely heavily on finger representation or on magnitude representation. Results are discussed in terms of the localizationist and the functional hypotheses.     

Memory strategies in absolute identification of “circular” pitch

Shepard (1964) has devised a sequence of synthesized tones that appear to constitute a “circular” pitch dimension; each tone in the sequence appears to be higher in pitch than the preceding one, and yet the first tone also seems higher than the last. Two series of such stimuli (a six-alternative and an eight-alternative set) were used to investigate memory processes in absolute identification performance when end stimuli are unavailable as possible anchors. Clear evidence was obtained for short-term anchoring strategies in this task, but none was obtained for the stable retention of those stimuli corresponding to the ends of the response continuum. The results are examined in the light of Eriksen and Hake’s (1957) subjective-standard hypothesis.     

Production of non-canonical sentences in agrammatic aphasia: limits in representation or rule application?

The study reported here compares two linguistically informed hypotheses on agrammatic sentence production, the TPH [Friedmann, N., & Grodzinsky, Y. (1997). Tense and agreement in agrammatic production: Pruning the syntactic tree. Brain and Language, 56, 397-425.] and the DOP [Bastiaanse, R., & van Zonneveld, R. (2005). Sentence production with verbs of alternating transitivity in agrammatic Broca's aphasia. Journal of Neurolinguistics, 18, 59-66]. To explain impaired production of non-canonical sentences in agrammatism, the TPH basically relies on deleted or pruned clause structure positions in the left periphery, whereas the DOP appeals to limitations in the application of movement rules. Certain non-canonical sentences such as object-questions and object-relative clauses require the availability of nodes in the left periphery as well as movement to these nodes. In languages with relatively fixed word order such as English, the relevant test cases generally involve a coincidence of left periphery and movement, such that the predictions of the TPH and the DOP are identical although for different reasons. In languages with relatively free word order such as German, on the other hand, it is possible to devise specific tests of the different predictions due to the availability of scrambling. Scrambled object sentences, for example, do not involve the left periphery but do require application of movement in a domain below the left periphery. A study was conducted with German agrammatic subjects which elicited canonical sentences without object movement and non-canonical scrambled sentences with object movement. The results show that agrammatic speakers have a particular problem with the production of scrambled sentences. Further evidence reported in the study from spontaneous speech, elicitation of object relatives, questions and passives and with different agrammatic subjects confirms that non-canonical sentences are generally harder to produce for agrammatics. These findings provide evidence in favor of the DOP and it will be argued that a cross-modal explanation of agrammatic deficits is possible if two factors--movement and canonicity--are taken into consideration.     

Thought suppression: specificity in agoraphobia versus broad impairment in social phobia?

The paradoxical effects of intended thought suppression have been linked to psychological disorders, specifically anxiety disorders. So far, the evidence for thought suppression playing a major role in the disorder is mixed. One important issue is whether thought suppression is impaired only for thoughts related to the disorder, or if the ability for mental control is generally impaired in anxiety patients. This study compared groups of agoraphobics and social phobics with a healthy control group. All subjects were asked to suppress two topics related to the respective central fear of the two disorders and one nonspecific topic. We found a rather specific deficit in thought suppression for the agoraphobics; that is, when compared with the control group, we found the biggest differences for the agoraphobic fear. The social phobics seem to be characterized by a general impairment of mental control, affecting specific and nonspecific stimuli. In addition, among several psychopathological variables, social anxiety proved to be the strongest predictor for problems with thought suppression. Taken together, there are several indicators that generally impaired thought suppression may be an important feature of social phobia.     

AQS security scores: What do they represent? A study in construct validation

In a sample of 129 Dutch 15‐month‐old infants, attachment security was assessed both with the Attachment Q‐Set (AQS; Waters, 1995) and with a short version of Ainsworth, Blehar, Waters, and Wall's (1978) Strange Situation (SSS). Infants classified as secure using the SSS had significantly higher AQS scores than insecure and disorganized infants in particular. At the AQS item level, disorganized infants were described as significantly more noncompliant, fussy, and angry relative to secure infants. When security as assessed using the SSS was controlled, the observed quality of parental interactive behavior, parental ego‐resilience, high levels of infant task orientation and pleasure, and low levels of infant anger proneness were found to explain significant and unique portions of the variance in the AQS security scores. The apparently unfavorable set of characteristics associated with low AQS security scores suggests such scores to predict later developmental problems. ©2004 Michigan Association for Infant Mental Health.     

Fuzziness in the Mind: Can Perception be Unconscious?

Recently, a new movement has arisen in the philosophy of perception: one that views perception as a natural kind. Strangely, this movement has neglected the extensive work in philosophy of science on natural kinds. The present paper remedies this. I start by isolating a widespread and influential assumption, which is that we can give necessary and sufficient conditions for perception. I show that this assumption is radically at odds with current philosophy of science work on natural kinds. I then develop an alternative, new view of perception. This new view takes as its starting point the dominant position on kinds in the life sciences: the homeostatic property cluster account. I show that, if you accept this view, then all of the putative cases of unconscious perception are more plausibly seen as cases where it is indeterminate whether the mental episode in question is an instance of perception.     

Directional bias in the mental representation of spatial events: nature or culture?

Previous research has shown a tendency for people to imagine simple sentences as evolving from left to right, with the sentence subject being located to the left of the object. In two cross-cultural studies comparing Italian and Arab participants, we investigated whether this bias is a function of hemispheric specialization or of directionality of written language (left to right in Italian, right to left in Arabic). Both studies found a reversal of directional bias in Arabs. Italians tended to position the subject to the left of the object, and Arabs tended to position the subject to the right of the object (Experiment 1); both groups were facilitated in a sentence-picture matching task when the subject was drawn in the position that it would usually occupy in the written language (left for Italians, right for Arabs; Experiment 2). In Experiment 2, an additional, language-independent facilitation was observed when action evolved from left to right, suggesting that both hemispheric specialization and scanning habit affect visual imaging.     

The representation of “false cognates” in the bilingual lexicon

The results of repetition priming studies with homographs such asbank suggest that semantic constraints restrict priming to the specific meaning invoked during the study phase. Cross-language priming studies with “false cognates” (words with similar form but unrelated meanings) suggest that form similarity may be sufficient to support repetition priming, and they do not therefore support this claim. The relevant studies have used language cues (e.g., seeing the word ESTATE in the context of other Italian words) as distinct from semantic cues (e.g.,inverno—estate) to constrain meaning, however, so that interpretation is correspondingly uncertain. The experiment described in this paper was designed to answer this question: Does sequential exposure to the English word pairmanor—estate during the study phase facilitate lexical decision to the second of these words during sequential exposure to the Italian word pairinverno—estate (i.e., winter-summer) during the test phase of the experiment? In the experiment reported below, interpretation of false cognates was constrained by meaning rather than language, and cross-language repetition priming was eliminated for false cognates. The results suggest that lexical representation in bilinguals is organized along morphological lines rather than by language.     

Aggression and psychological problems in juvenile male delinquents versus controls in russia: Alternative ways of “letting off steam”?

The purpose of this study is to investigate possible relationships between various subtraits of aggression and psychological symptoms in a sample of male delinquents. One hundred eighty-nine subjects from a juvenile correction center for delinquent adolescents and 117 control subjects from secondary schools in Arkhangelsk, Russia, were assessed by means of the Aggression Questionnaire and the Youth Self-Report. Significant correlations between hostility, anger, and some psychological problems (e.g., Withdrawn, Anxious/Depressed, Thought Problems) were found in both groups. At the same time, physical and verbal aggression was almost exclusively related to aggressive and delinquent behavior. The findings lend support to our proposed interactional model in which excitation, as a result of the interplay between cognitions and emotions, could be expressed either as socially accepted behavior, aggressive behavior, or psychological and somatic symptoms.