Brain activations associated with shifts in response criterion on a recognition test.

Sensitivity and bias can be manipulated independently on a recognition test. The goal of this fMRI study was to determine whether neural activations associated with manipulations of a decision criterion would be anatomically distinct from neural activations associated with manipulations of memory strength and episodic retrieval. The results indicated that activations associated with shifting criteria (a manipulation of bias) were located in bilateral regions of the lateral cerebellum, lateral parietal lobe, and the dorsolateral prefrontal cortex extending from the supplementary motor area. These regions were anatomically distinct from activations in the prefrontal cortex produced during memory-based retrieval processes (manipulations of sensitivity), which tended to be more medial and anterior. These later activations are consistent with previous studies of episodic retrieval. Determining patterns of neural activations associated with decision-making processes relative to memory processes has important implications for Cognitive Neuroscience, including the use of these patterns to compare memory models in different paradigms.     

Book reviews

Hansel, C . E. M. ESP and Parapsychology: A Critical Re-Evaluation. Buffalo: Prometheus Books. 1980. Pp. 325. Hardback 415.95; paperback £7.95. ISBN 0 87975 119 3.

Marks, D. and Kamman, R. The Psychology of the Psychic. Buffalo: Prometheus Books. 1980. Pp. 232. Hardback £16.95; paperback 48.95. ISBN 0 87975 121 5.

Atkin, R. Multidimensional Men. Harmondsworth: Penguin. 1981. £2.95. ISBN o 14 005478 2.

Frith, U. (Ed.). Cognitive Processes in Spelling. London: Academic Press. 1980. Pp. 560. £17.00. ISBN 0 12 268660 8.

Herron, J. (Ed.). Neuropsychology of Left-Handedness. Perspectives in Neurolinguistics and Psycholinguistics. London: Academic Press. 1980. Pp. xiv+357. £13.50. ISBN 0 12 343150 6.

Welford, A. T. (Ed.). Reaction Times. London: Academic Press. 1980. Pp. ix+418. £27-80. ISBN 0 12 742880 1.

Anderson, J. R. Cognitive Psychology and its Implications. San Francisco: Freeman. 1980. Pp. xviii+503. £8.10.

Bolton, N. (Ed.). Philosophical Problems in Psychology. London: Methuen. 1979. £8.50. Pp. xiii+207. ISBN 0 416 70980 X.     

Finding words in a language that allows words without vowels

Across many languages from unrelated families, spoken-word recognition is subject to a constraint whereby potential word candidates must contain a vowel. This constraint minimizes competition from embedded words (e.g., in English, disfavoring win in twin because t cannot be a word). However, the constraint would be counter-productive in certain languages that allow stand-alone vowelless open-class words. One such language is Berber (where t is indeed a word). Berber listeners here detected words affixed to nonsense contexts with or without vowels. Length effects seen in other languages replicated in Berber, but in contrast to prior findings, word detection was not hindered by vowelless contexts. When words can be vowelless, otherwise universal constraints disfavoring vowelless words do not feature in spoken-word recognition.     

A modified counterconditioning procedure prevents the renewal of conditioned fear in rats

Two studies using an ABA design examined the Extinction and renewal of conditioned barpress suppression. Following lights-off and foot shock pairings in Context A, rats were placed in Context B and were given either a standard counterconditioning procedure where the lights-off CS was paired with a novel food US delivered freely or a modified counterconditioning procedure where CS-US pairings only occurred if the rat earned the US by performing a required behavior during the CS. Results indicated that the modified counterconditioning procedure thwarted ABA renewal but the conventional counterconditioning procedure did not reduce ABA renewal any more than nonreinforced exposure to the CS alone. Furthermore, the response required during the modified counterconditioning procedure could be one used as a baseline response during Acquisition of fear or it could be a novel response. Implications of the results for theories of Extinction and renewal of fear are discussed.     

The Possible-Word Constraint in the Segmentation of Continuous Speech

We propose that word recognition in continuous speech is subject to constraints on what may constitute a viable word of the language. This Possible-Word Constraint (PWC) reduces activation of candidate words if their recognition would imply word status for adjacent input which could not be a word - for instance, a single consonant. In two word-spotting experiments, listeners found it much harder to detectapple,for example, infapple(where [f] alone would be an impossible word), than invuffapple(wherevuffcould be a word of English). We demonstrate that the PWC can readily be implemented in a competition-based model of continuous speech recognition, as a constraint on the process of competition between candidate words; where a stretch of speech between a candidate word and a (known or likely) word boundary is not a possible word, activation of the candidate word is reduced. This implementation accurately simulates both the present results and data from a range of earlier studies of speech segmentation.     

Nonadversarial Methods for Sensitizing Jurors to Eyewitness Evidence

Tested the effects, on juror decision making, of court-appointed expert testimony and judge's instructions designed to sensitize jurors to eyewitness evidence. Subjects ( N = 144) viewed a videotaped trial in which the primary evidence was the testimony of and identification by an eyewitness. Three levels of expert advice (court-appointed expert, judge's instructions, no expert advice) were crossed with two levels of witnessing and identification conditions and two levels of witness confidence The court-appointed expert produced skepticism toward the identification but did not improve juror sensitivity to the eyewitness evidence. The judge's instructions produced neither skepticism or sensitization effects.     

Constraints of vowels and consonants on lexical selection: Cross-linguistic comparisons

Languages differ in the constitution of their phonemic repertoire and in the relative distinctiveness of phonemes within the repertoire. In the present study, we asked whether such differences constrain spoken-word recognition, via two word reconstruction experiments, in which listeners turned non-words into real words by changing single sounds. The experiments were carried out in Dutch (which has a relatively balanced vowel-consonant ratio and many similar vowels) and in Spanish (which has many more consonants than vowels and high distinctiveness among the vowels). Both Dutch and Spanish listeners responded significantly faster and more accurately when required to change vowels as opposed to consonants; when allowed to change any phoneme, they more often altered vowels than consonants. Vowel information thus appears to constrain lexical selection less tightly (allow more potential candidates) than does consonant information, independent of language-specific phoneme repertoire and of relative distinctiveness of vowels.     

Effects of stimulus characteristics and sex of subject on perceived emotion

To determine the influence of pupil size, eye size, sex of stimulus face, and sex of subject on perceived emotion, 308 college students filled in missing features on stimulus faces. Each face was independently rated by two male judges on a continuum of negative to positive emotion. Analysis indicated that sex of subject was the only variable to affect perceived emotion. Women (n = 175) tended to draw faces that were judged to be more positive than faces drawn by men (n = 133).     

The relative accessibility of phonemes and syllables

Previous research comparing detection times for syllables and for phonemes has consistently found that syllables are responded to faster than phonemes. This finding poses theoretical problems for strictly hierarchical models of speech recognition, in which smaller units should be able to be identified faster than larger units. However, inspection of the characteristics of previous experiments’ stimuli reveals that subjects have been able to respond to syllables on the basis of only a partial analysis of the stimulus. In the present experiment, five groups of subjects listened to identical stimulus material. Phoneme and syllable monitoring under standard conditions was compared with monitoring under conditions in which near matches of target and stimulus occurred on no-response trials. In the latter case, when subjects were forced to analyze each stimulus fully, phonemes were detected faster than syllables.