Verbal retention deficits in aphasic and amnesic patients.

Five different groups of patients (aphasics, alcoholic Korsakoffs, nondominant hemisphere patients, alcoholics, and control patients) were asked to detect either repeated letters, repeated words, rhyming words, or words from the same category during the reading of a list. It was discovered that the number of intervening words had a greater effect on the aphasics for all conditions than it did for the other groups. However, when the rate of presentation was slowed, the aphasics showed considerable improvement while the other groups maintained their same level of performance. The Korsakoff patients were impaired only on the semantic task (same category inclusion) and did not improve at the slower presentation rate. An interpretation based on speed and level of information processing abilities is given.     

Lexical decisions in the right and left cerebral hemispheres

Subjects performed a lexical decision task in which letter-strings were presented unilaterally and tachistoscopically to the right and left visual fields. Four types of letter-strings were used: high frequency words, low frequency words, pronounceable nonwords, and unpronounceable nonwords. Measures of reaction time and error rate both showed a right visual field advantage for both classes of words and no difference between the hemispheres for either class of nonword. It was concluded that meaning is a more salient parameter of wordness than is pronounceability. Possible mechanisms for processing words presented to the left visual field were discussed.     

Auditory-verbal short-term memory impairment and conduction aphasia

The specific impairment of performance on repetition tasks has classically been identified with conduction aphasia. It is argued that this impairment can be subdivided and a deficit in span performance distinguished from that of the reproduction of single words. An explanation of the span deficit in terms of auditory-verbal short-term memory is preferred to hypotheses involving disconnections or damage to order retention systems. It is shown that a short-term memory component is present in many patients previously classified as conduction aphasics.     

The perception of dichotic chords by hemispherectomized subjects

Hemispherectomized subjects display a strong ear dominance in their perception of dichotically presented two-tone chords. The frequency of the tone presented to the ear contralateral to the remaining hemisphere dominated the pitch mixture of the chord. The described effect does not vary with the age at which the hemispherectomy was performed. These results are consistent with the hypothesis, developed to account for findings in normal subjects, that the pitch mixture of a dichotic chord is determined by a subcortical pitch processor. The effects observed in hemispherectomized subjects may result from an interruption of an efferent pathway from the cortex to the subcortical pitch processor or from an asymmetrical degeneration of the processor which may be located in the thalamus (medial geniculate).     

Cognitions related to anxiety: a pilot study of treatment

In general, where anxiety appears to have a specific external focus, such as the situations which are avoided by phobic patients, treatment involving systematic exposure to those situations seems to be effective. This is less appropriate, or even impossible, where anxiety is not dependent on any external circumstance, but is described by the patient as occurring at any time or place, either chronically over long periods, or acutely in the form of ‘panic attacks’. These patients with ‘generalised’ anxiety often describe internal cues for anxiety either in the form of thoughts (e.g. worry over a current problem) or somatic (e.g. chest sensations interpreted as possible heart disease). Beck et al. (1974) has suggested that on interview, all patients diagnosed as suffering from diffuse or generalised anxiety can report specific ideas or other cognitive cues which are associated with anxiety. These usually concern possible traumatic events, such as illness and death, or social rejection. Clearly Beck has in mind the possibility that these cognitions have the effect of inducing anxiety, although even if the validity of the subjective reports were to be accepted, the problem remains of whether the relationship between mood state and cognitions is causal and if so, in which direction it operates. Obviously a causal relationship may also operate in both directions simultaneously, to form a ‘vicious circle’ in which each exacerbates the other. To establish whether there is a sense in which particular cognitions contribute causally to anxious mood, it would be necessary to find a method of manipulating the type or frequency of cognitions thought to be operating in this way.

One obvious possibility is that of ‘thought-stopping’: that is, patients could be taught to identify thoughts which are associated with anxiety and stop them in the usual way (Wolpe, 1973, p. 211) e.g. by' shouting stop, and substituting an alternative thought. The present study was planned as a pilot experiment to determine (i) if appropriate anxiety related cognitions could be elicited from a series of patients with generalised anxiety, (ii) if the reported frequency of such thoughts could be modified by a thought-stopping technique, and (iii) if any changes in thought frequency were associated with improvements in mood.

Clearly there are many ‘non-specific’ features involved in thought-stopping which could also have therapeutic effects on mood. For this reason it was necessary to include an alternative procedure, not directed at reducing thought frequency, but having the same degree of plausibility to patients, and preferably to therapists. The control procedure chosen for this purpose was modelled on desensitisation, in which patients were encouraged to allow the supposedly anxiety-provoking thoughts into their mind and tolerate them, rather than attempt to stop them. In summary, the study employed a relaxation training phase as a base-line, followed by a cross-over design in which the two treatment phases of thought-stopping and ‘cognitive desensitisation’ were given to each patient, in balanced order.     

Treatment of dental fears by imaginal flooding and rehearsal of coping behaviour

All combinations of high versus low arousal imaginal flooding, and coping versus no-coping imaginal rehearsal, were compared in the modification of dental fear. About one half of all subjects seen successfully completed dental treatment, although significant differences were found between groups in anxiety reduction before and during dental examination, which favoured the low arousal flooding groups. Coping rehearsal did not influence anxiety, but interacted with arousal level of flooding to determine subsequent dental attendance. The results suggest that flooding without coping rehearsal had little effect at high levels of arousal, but good results at low levels. Flooding with coping rehearsal on the other hand, had mixed results. At high arousal levels avoidance was reduced but not anxiety, while at low levels anxiety was reduced but not avoidance. The implications for further research on coping rehearsal are discussed.