Communicative functions of directional verbal probabilities: Speaker’s choice,listener’s inference,and reference points

Verbal probabilities have directional communicative functions, and most can be categorized as positive (e.g., “it is likely”) or negative (e.g., “it is doubtful”). We examined the communicative functions of verbal probabilities based on the reference point hypothesis According to this hypothesis, listeners are sensitive to and can infer a speaker’s reference points based on the speaker’s selected directionality. In four experiments (two of which examined speakers’ choice of directionality and two of which examined listeners’ inferences about a speaker’s reference point), we found that listeners could make inferences about speakers’ reference points based on the stated directionality of verbal probability. Thus, the directionality of verbal probabilities serves the communicative function of conveying information about a speaker’s reference point.     

Genetic and environmental influences on the Verbal-Perceptual-Image Rotation (VPR) model of the structure of mental abilities in the Minnesota study of twins reared apart

In previous papers [Johnson, W., & Bouchard Jr., T. J. (2005a). Constructive Replication of the Visual-Perceptual-Image Rotation (VPR) Model in Thurstone's (1941) Battery of 60 Tests of Mental Ability. Intelligence, 33, 417–430.] [Johnson, W., & Bouchard Jr., T. J. (2005b). The Structure of Human Intelligence: It's Verbal, perceptual, and image rotation (VPR), not Fluid and Crystallized. Intelligence, 33, 393–416.] we have proposed the Verbal, perceptual, and image rotation (VPR) model of the structure of mental abilities. The VPR model is hierarchical, with a g factor that contributes strongly to broad verbal, perceptual, and image rotation abilities, which in turn contribute to 8 more specialized abilities. The verbal and perceptual abilities, though separable, are highly correlated, as are the perceptual and mental rotation abilities. The verbal and mental rotation abilities are much less correlated. In this study we used the twin sample in the Minnesota Study of Twins Reared Apart to estimate the genetic and environmental influences and the correlations among them at each order of the VPR model. Genetic influences accounted for 67–79% of the variance throughout the model, with the exception of the second-stratum Content Memory factor, which showed 33% genetic influence. These influences could not be attributed to assessed similarity of rearing environment. Genetic correlations closely mirrored the phenotypic correlations. Together, these findings substantiate the theory that the entire structure of mental abilities is strongly influenced by genes.     

Do pointing gestures by infants provoke comments from adults?

In the field of developmental psychology, there is speculation that pointing gestures by infants are good precursors of infant language acquisition, and some researchers have found correlations between these pointing gestures and some indices of language acquisition. Infants’ pointing gestures are presumably related to language acquisition because they provoke verbal responses from adults. To test this, seven boys and six girls were observed during free play time in a nursery classroom, and post-pointing and matched-control data were collected. Comparison between these data confirmed that the nursery staff spoke to infants at a significantly earlier stage in post-pointing sequences, compared with control sequences, indicating that pointing gestures elicit verbal responses from adult caregivers.     

Differences in numeric,verbal, and spatial reasoning between engineering and literature students through a neurocognitive lens

This study used electroencephalography to investigate the brain activations of college students of various disciplines when they responded to questions in numeric, verbal, and spatial reasoning tasks. In total, 15 engineering students and 15 literature students were recruited in this experiment and were asked to respond to 12 intelligence test questions. The results were as follows: (i) the participants’ brain activations increased in the frontoparietal network during the numeric reasoning task, and the spectral power in the right anterior temporal cortex was generally higher in the literature students than in the engineering students. (ii) Activations of the language network were observed during the verbal reasoning task, and the spectral power in the right-biased posterior frontal cortex was generally higher in the literature students than in the engineering students; by contrast, the spectral power in the left lateral frontal cortex was generally higher in the engineering students than in the literature students. (iii) The participants’ brain activations increased in the spatial processing network during the spatial reasoning task, and the spectral power in the right posterior temporal cortex was generally higher in the literature students than in the engineering students.     

Comparing detailed and less detailed pre-lineup instructions

It is generally agreed that proper pre-lineup instructions can reduce the rate of mistaken identifications of innocent suspects. However, the exact nature of these instructions has not been empirically established. We compared the effects of the detailed pre-lineup instructions recommended by the US Department of Justice to a simple instruction that the perpetrator may or may not be present. Both forms of unbiased instructions significantly reduced mistaken identifications when compared with biased instructions. Comparison of performance using the utility-based analysis deviation from perfect performance demonstrated that unbiased instructions are to be preferred under assumptions of low base rates or high costs of mistaken identifications and do as well as biased instructions under assumptions of high base rates or low cost of misidentification.     

Refining the blank line-up procedure: How should we instruct eyewitnesses?

Presenting a blank line-up—containing only fillers—to witnesses prior to showing a real line-up might be useful for screening out those who pick from the blank line-up as unreliable witnesses. We show that the effectiveness of this procedure varies depending on instructions given to witnesses. Participants (N = 462) viewed a simulated crime and attempted to identify the perpetrator from a line-up approximately 1 week later. Rejecting a blank line-up was associated with greater identification accuracy and greater diagnosticity of suspect identifications, but only when witnesses were instructed prior to the blank line-up that they would view a series of line-ups; the procedure was ineffective for screening when witnesses were advised they would view two line-ups or received no instruction. These results highlight the importance of instructions used in the blank line-up procedure, and the need for better understanding of how to interpret choosing patterns in this paradigm.     

Individual differences in sensory integration predict differences in time perception and individual levels of schizotypy

To interact functionally with our environment, our perception must locate events in time, including discerning whether sensory events are simultaneous. The Temporal Binding Window (TBW; the time window within which two stimuli tend to be integrated into one event) has been shown to relate to individual differences in perception, including schizotypy, but the relationship with subjective estimates of duration is unclear. We compare individual TBWs with individual differences in the filled duration illusion, exploiting differences in perception between empty and filled durations (the latter typically being perceived as longer). Schizotypy has been related to both these measures and is included to explore a potential link between these tasks and enduring perceptual differences. Results suggest that individuals with a narrower TBW make longer estimates for empty durations and demonstrate less variability in both conditions. Exploratory analysis of schizotypy data suggests a relationship with the TBW but is inconclusive regarding time perception.     

Asymmetry of attentional set in rhesus monkeys learning colour and shape discriminations

We trained rhesus monkeys on six visual discrimination problems using stimuli that varied in both shape and colour. For one group of animals shape was always relevant in these six problems, and colour always irrelevant, and for the other animals vice versa. During these “intradimensional shifts” (ID) the problems were learned at equal rates by the two groups, shape-relevant and colour-relevant. We then trained three further problems in which the other dimension was now relevant (“extradimensional shifts”, ED). The animals showed slower learning when shifting from colour-relevant to shape-relevant, but not when shifting from shape-relevant to colour-relevant. These results show that monkeys' ability to selectively attend to a relevant stimulus dimension and to ignore an irrelevant dimension depends on the experimenter's choice of relevant and irrelevant dimensions.     

Similarity and binding in memory: Bound to be detrimental

The process of binding information from different modalities and sources into an object is ubiquitous in cognition and has been a problem for research and modelling efforts in psychology. This process has been considered by most researchers as necessarily always beneficial to memory. In the present study we provide evidence that binding can be detrimental through the propagation of vulnerabilities to interference. Phonologically similar and dissimilar letters were presented sequentially at different locations on a computer monitor. Participants had to recall either the letters in their order of presentation or the spatial locations at which the letters had appeared. Whether binding was encouraged or not—providing prior knowledge of which dimension to remember—phonological similarity had a detrimental effect on recall of locations. Such a finding poses a challenge to the view that binding is the panacea in enhancing memory capacity.     

Differential effects of articulatory suppression on cue-switch and task-switch trials in random task cueing with 2:1 mapping

Recent studies have revealed that verbal representations play an important role in various task-switching situations. This study examined whether verbal representations contribute to the actual switching process using random task cueing with two cues per task. This procedure allowed us to produce a trial in which the cue switched, but the task repeated, thereby separating the cue-switching process from the actual task-switching process. Participants performed colour or shape judgements that were initiated by an arbitrary symbol cue (Experiments 1 and 2) or a kanji cue (Experiment 3) under control, articulatory-suppression, and foot-tapping conditions. In Experiments 1 and 2 with the arbitrary cues, articulatory suppression impaired performance in only the cue-switch condition. In Experiment 3, in which a kanji cue indicated the upcoming task name, articulatory suppression did not have any effects. These results suggest that the involvement of verbal representations in random task cueing is based on the cue-switching process rather than on the task-switching process.