Neil Morris

Functional equivalence of verbal and spatial information in serial short-term memory.

Performance on a test of serial memory for the spatial position of a sequence of dots showed similarities to typical results from the serial recall of verbal material: a marked increase in error with increasing list length, a modest rise in error as retention interval increased, and bow-shaped serial position curves. This task was susceptible to interference from both a spatial task (rote tapping) and a verbal task (mouthed articulatory suppression) and also from the presence of irrelevant speech. Effects were comparable to those found with a serial verbal task that was generally similar in demand characteristics to the spatial task. As a generalization, disruption of the serial recall of visuospatial material was more marked if the interference conditions involved a changing sequence of actions or materials, but not if a single event (tap, mouthed utterance, or sound) was repeated.

Working Memory and Conditional Reasoning

Little is known about the role of working memory in conditional reasoning. This paper reports three experiments that examine the contributions of the visuo-spatial scratch pad (VSSP), the articulatory loop, and the central executive components of Baddeley and Hitchs (1974) model of working memory to conditional reasoning. The first experiment employs a spatial memory task that is presented concurrently with two putative spatial interference tasks (tapping and tracking), articulatory suppression, and a verbal memory load. Only the tracking and memory load impaired performance, suggesting that these tap the VSSP and central executive, respectively. Having established the potency of these interference tasks two further experiments examined the effects of tapping and tracking (Experiment 2) and articulation and memory load (Experiment 3) on a conditional reasoning task. Neither tracking nor tapping affected the number of inferences accepted or response latency. Articulation also failed to affect conditional reasoning but memory load selectively reduced acceptance of modus tollens inferences. These results are discussed in terms of both rule-based and mental models theories of reasoning. While these data cannot discriminate between the two perspectives they provide support for one of the central assumptions in each: that some errors in reasoning are attributable directly to working memory demands. Taken together these experiments suggest that conditional reasoning requires an abstract working memory medium for representation; it does not require either the VSSP or the articulatory loop. It is concluded that the central executive provides the necessary substrate.

Exploring the visuo-spatial scratch pad.

A series of four studies examines the relationship between the visuo-spatial scratch pad, the central executive and the articulatory loop. For this purpose a visuo-spatial memory task that does not have a large verbal component was developed. In Experiment 1 this task was used to demonstrate that the scratch pad, although functionally independent of the articulatory loop, is subject to interference from a tracking task. Experiment 2 examined the locus of interference of the tracking task with spatial memory. It was shown that interference is confined to the encoding phase; post presentation tracking does not disrupt visuo-spatial representation. Experiment 3 demonstrated that the tracking task employed requires some central executive resources. The final experiment examined the effect of a near-span consonant memory load on the spatial memory task. Disruption only occurred when the verbal load preceded, or was concurrent with, the spatial task. The results suggest that central executive resources are probably required to operate the scratch pad in most circumstances. However, minimal central capacity is required for maintenance rehersal.

Role of motion signals in recognizing subtle facial expressions of emotion.

Three studies investigated the importance of movement for the recognition of subtle and intense expressions of emotion. In the first experiment, 36 facial emotion displays were duplicated in three conditions either upright or inverted in orientation. A dynamic condition addressed the perception of motion by using four still frames run together to encapsulate a moving sequence to show the expression emerging from neutral to the subtle emotion. The multi-static condition contained the same four still presented in succession, but with a visual noise mask (200 ms) between each frame to disrupt the apparent motion, whilst in the single-static condition, only the last still image (subtle expression) was presented. Results showed a significant advantage for the dynamic condition, over the single- and multi-static conditions, suggesting that motion signals provide a more accurate and robust mental representation of the expression. A second experiment demonstrated that the advantage of movement was reduced with expressions of a higher intensity, and the results of the third experiment showed that the advantage for the dynamic condition for recognizing subtle emotions was due to the motion signal rather than additional static information contained in the sequence. It is concluded that motion signals associated with the emergence of facial expressions can be a useful cue in the recognition process, especially when the expressions are subtle.

Habituation to irrelevant speech: Effects on a visual short-term memory task

The Baddeley and Hitch (1974) formulation of short-term or working memory embodied a phonological store within the articulatory loop component of the model. Later formulations specifically postulated an acoustic filter that endowed only speech-like stimuli with obligatory access to this phonological store. This paper presents evidence that this phonological store may have two filters, one of which is subject to habituation and can therefore attenuate the entry of irrelevant speech, thus undermining the obligatory access assumption of the model. An experiment is reported in which subjects were presented with a habituation period comprising 20 min of irrelevant speech— speech to be ignored by the subject—before a test phase in which a visually presented serial recall task with concurrent irrelevant speech was performed. The effect of irrelevant speech, which impairs performance on the primary task when there is no habituation phase, is reduced markedly in those conditions where the speech used in the habituation phase is the same as that used in the test phase, if the irrelevant speech is in a language different from that presented during the subsequent trials or if the habituator is a hummed version of the irrelevant speech passage. When a nonspeech sound(pink noise) is used in the habituation phase, a large irrelevant speech effect is found in the test phase. Morris, Quayle, and Jones (1989) found that humming did not produce an irrelevant speech effect, which suggests that the first filter is permeable to humming but that the second filter is not. The results of the habituation study indicate that the first filter is permeable to all speech sounds but not to other acoustic input and that it has some attenuating device. A second filter appears to extract more complex speech features and thus excludes humming. It is concluded that irrelevant speech does not have obligatory access to this phonological store when exposure is prolonged, and that it has unvarying spectral features.

Recognising subtle emotional expressions: The role of facial movements

Two studies investigated the importance of dynamic temporal characteristic information in facilitating the recognition of subtle expressions of emotion. In Experiment 1 there were three conditions, dynamic moving sequences that showed the expression emerging from neutral to a subtle emotion, a dynamic presentation containing nine static stills from the dynamic moving sequences (ran together to encapsulate a moving sequence) and a First–Last condition containing only the first (neutral) and last (subtle emotion) stills. The results showed recognition was significantly better for the dynamic moving sequences than both the Dynamic-9 and First–Last conditions. Experiments 2a and 2b then changed the dynamics of the moving sequences by speeding up, slowing down or disrupting the rhythm of the motion sequences. These manipulations significantly reduced recognition, and it was concluded that in addition to the perception of change, recognition is facilitated by the characteristic muscular movements associated with the portrayal of each emotion.

Drinking glucose improves listening span in students who miss breakfast

Low blood sugar level resulting from fasting has been shown to reduce performance on a number of cognitive tasks. In this study, 80 non-diabetic A-level students missed breakfast. They completed a version of Daneman and Carpenters Listening Span Test at 9.00 a.m. Half were then given a drink containing glucose, while the other half received a saccharine drink matched for taste. After 20 minutes, both groups completed another form of the Listening Span Test. A subset of the sample had their blood glucose levels determined immediately before the drink and again before the second application of the test. Blood glucose levels did not change, but listening span performance significantly improved after a glucose drink yet not after a saccharine drink. It is concluded that missing breakfast does not seriously affect blood sugar levels in healthy young students, but listening span performance which is a good predictor of listening comprehension is improved when fasting individuals imbibe a glucose-rich drink, although not when a saccharine drink is drunk. Ideally students should eat breakfast, but if this is omitted, then a glucose snack or drink before the first class may reverse any adverse effects.

Mood and cognition in pregnant workers

Thirty-eight working women, in their late second trimester or early third trimester of pregnancy, volunteered to fill out the Cognitive Failures Questionnaire and the UWIST Mood Adjective Checklist. In addition they provided information on the number of children they already had, the nature of their employment and their education level. The latter information was used to select a match for each pregnant worker from a larger sample of non-pregnant female workers. The results revealed no differences in the level of cognitive failures between the two groups. However, CFQ score was a better predictor of mood in the pregnant subjects, suggesting mood changes may be more closely related to perceived cognitive competency during pregnancy. The implications of this are discussed. With respect to mood sub-scales, non-pregnant workers scored higher on Energetic Arousal than pregnant workers. There were no differences on other mood sub-scales. It is argued that the cognitive efficiency of workers is not compromised by pregnancy but steps should be taken to ensure that work load is adjusted to take account of the self-reported reduced arousal that may arise.

Subclinical delusional ideation and a self‐reference bias in everyday reasoning

Previous studies (e.g. Moller & Husby, 2000; Blackwood et al., 2004) have revealed that delusional thinking is accompanied by an exaggerated focus upon the self and upon stimuli that are perceived to be related to the self. The objective was to examine whether those high in subclinical delusional ideation exhibit a heightened tendency for self-reference. Using a mixed design, healthy individuals, classified into high- and low-scoring groups on the Peters et al. Delusions Inventory (Peters, Day, & Garety, 1996), were compared on everyday reasoning tasks across three experiments. High-PDI scorers, in contrast to the low-PDI group, rated self-referent objections to everyday arguments as stronger than other-referent objections and formulated more self-referent assertion-based objections to everyday arguments. The findings support the notion that subclinical delusional ideation is linked to a self-reference bias, which is evident in the sort of everyday thinking that people engage in when forming or evaluating their beliefs and which may contribute to delusion formation.

Linguistic Androgyny on MySpace

This article examines gender differences in the use of gendered language features in “about me” sections and forum comments on MySpace. Although men and women communicated in more stereotypically gendered ways in the forums, linguistic androgyny prevailed in “about me.” It is likely that “about me” sections provoke a more gender-neutral style of communication, as they are the self-representation in MySpace. Moreover, presenting oneself androgynously will be more appealing to a wider spectrum of users.