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Biomedical subjects

L R Hartley

Publications and source records attributed to L R Hartley.

At least 19 recordsLinked to original sources
PubMed1995

Aberrant driving behaviour: errors and violations.

The present study was a replication of the research of Reason et al. (1990). Its aim was to confirm the distinction between driving errors and violations in a Western Australian driving population. Sixty-one male drivers and 74 female drivers completed a questionnaire containing items on driver demographics, driving penalties incurred, driving convictions and accident history and driver behavioral aberrations drawn from the Driver Behaviour Questionnaire (DBQ). In agreement with Reason et al. factor analysis revealed three factors; in the present study these were general errors, dangerous errors, and dangerous violations. Young drivers committed more dangerous errors and dangerous violations than older drivers. Females reported more dangerous errors than males. Males reported more dangerous violations than females. Drivers who reported a high level of road exposure and those who reported having been convicted for speeding reported more dangerous violations. Differences in the results of the two studies can largely by accounted for by differences in the representation of age and gender in the two populations studied.

Accidents, Traffic↗
PubMed1991

Chlorpromazine and the lateralisation of the perception of emotion.

In a double-blind design, sixteen volunteer students were administered 50 mg of chlorpromazine or a placebo in tablet form on separate occasions, two hours prior to testing. The test was a lexical decision paradigm involving unilateral presentation of pairs of neutral, positive and negative emotional words and nonwords to the left or right visual fields. Reaction time to identify words and nonwords was recorded. Neutral stimuli were processed faster in the left hemisphere, while negative stimuli were processed faster in the right hemisphere. Chlorpromazine improved speed of response for neutral stimuli presented to the right hemisphere and for affective stimuli presented to the left hemisphere. Thus chlorpromazine seems to benefit right hemisphere processing of nonaffective stimuli and benefit left hemisphere processing of affective stimuli. Chlorpromazine appeared to have a different impact on neutral and affective words, and on the right and the left hemispheres. The general effect of chlorpromazine was to reduce lateralisation. It was suggested that this occurred because chlorpromazine blocked dopamine and possibly other neurotransmitters.

Adult↗
PubMed1990

Listening, priming and emotion under a neuroleptic drug.

The authors previously found that emotional arousal increased the asymmetry of facial and other lateralised expressive behaviours. Chlorpromazine equalized the symmetry of behaviour by reducing emotional arousal rather than by blocking all behaviour. These results raise the question of whether the perception of emotion is also lateralised and similarly influenced by chlorpromazine. Sixteen student volunteers were administered placebo and 50 mg of chlorpromazine in tablet form on separate occasions two hours before carrying out two tests of lateralised perception. Dichotic recognition of positive and neutral but not negative emotional words revealed a right ear advantage. No drug effect was observed. The speed of recognition of words and nonwords was also examined following emotionally toned priming words lateralised to the visual hemifields. This task showed some parallel findings to the dichotic test but some lateralised effect of the drug was observed.

Adult↗
PubMed1989

Lateralization of emotional expression under a neuroleptic drug.

Sixteen student volunteers were administered placebo and 50 mg of chlorpromazine (CPZ) in tablet form, on separate occasions, two hours before testing. Whilst volunteers related pleasant and unpleasant personal life events, the frequency and intensity of expressions on the left and right sides of the face were rated by independent observers. Subsequently the valence of the narration was also rated. Similar to a previous study facial expressions during negative emotions were expressed more often and intensely in the left face but positive emotions were bilaterally represented. CPZ neutralised the emotion on both sides of the face, irrespective of whether it was positive or negative. However, because negative emotions were almost completely lateralised to the left face the drug's effect on this emotion was most pronounced on this side. Independent ratings of the narration of the life events showed CPZ made them more pleasant. It is suggested that emotional arousal increases the asymmetry of behaviours when these are unilaterally represented or controlled. CPZ may equalize the symmetry of behaviour by reducing emotional arousal rather than by blocking all behaviour.

Adolescent↗
PubMed1986

Scopolamine and the control of attention in humans.

Recent work with humans and animals has suggested that the cholinergic system plays an important role in the active control of attention. This study was designed to investigate the effects of scopolamine upon subjects' ability to utilize knowledge of the spatial probability bias in a display in the detection of briefly-presented target letters. Results showed a significant interaction between drug condition (scopolamine 0.9 mg versus Placebo) and target location probability, which indicated that detection of targets in high probability locations decreased under the drug, while detection in low probability locations increased. These results offer support for the notion that scopolamine reduces the efficiency of information encoding because it impairs the optimal utilization of attentional resources.

Adult↗
PubMed1986

The effects of nicotine upon memory and problem solving performance.

This study examined the effects of 4 mg nicotine and placebo upon problem solving performance in word and number tasks, and subsequent recall and recognition of the answers to these problems. The results demonstrated that the drug had no effect upon the subject's ability to generate the correct answers to the problems, but that immediate and delayed recall and recognition were significantly impaired. These data clearly do not support the view that nicotine, without exception, enhances information processing, and it was suggested that the effects of nicotine upon information retrieval may be specific to tasks which assess episodic memory in the absence of retrieval cues or a problem solving context.

Adolescent↗
PubMed1983

Arousal, temporal and spatial uncertainty and drug effects.

1. Due to the multiplicity of a drugs pharmacological action a precise prediction of its behavioural effects is not possible. 2. A heuristic classification of drug effects on man should emphasize similarities and differences between different pharmacological classes. 3. A comparison of several drugs acting on the catecholamine system suggests they influence stimulus selection by affecting the organism's preparation. 4. Sedative - hypnotics, including alcohol, appear to act on different mechanisms, slowing responding. 5. The action of these classes of drugs on memory also appeared to be dissimilar.

Adult↗
PubMed1983

The effect of beta adrenergic blocking drugs on speakers' performance and memory.

Propranolol 40 mg was compared with a matched placebo tablet in its effect on the performance of anxious and non-anxious human volunteers. Subjects were required to give a brief speech, which was video-taped and later rated by trained observers for signs of anxiety; propranolol clearly reduced rated anxiety in the non-verbal behaviour of anxious subjects, as well as the anxiety observed in the speech of the anxious compared to the non-anxious. It also affected self-reported anxiety in the anxious, and reduced the pulse rate of anxious and non-anxious alike. Subjects were also prompted, by being given the first letter, to recall both difficult and easy words, drawn from selected verbal categories; propranolol impaired recall of difficult items in the memory of anxious subjects. Results were interpreted as showing a central as well as peripheral role for propranolol in blocking adrenergic receptors' activity in anxiety.

Adult↗
PubMed1982

Anxiety, diazepam and retrieval from semantic memory.

Diazepam, an anxiolytic, was administered to 16 undergraduate volunteers in a double-blind design. Eight subjects were selected to be high in State and Trait anxiety and were slow in recall on a semantic memory task compared to non-anxious subjects. Instead of alleviating this detrimental effect of anxiety on memory, diazepam slowed recall in both the anxious and non-anxious.

Adolescent↗
PubMed1982

Diazepam and self or externally paced letter matching tasks.

1. Sixteen human volunteers were administered 5mg of valium or placebo on 2 visits to the laboratory. 2. Their performance in a letter matching task was studied when it was self-paced and when externally-paced by the experimenter. 3. Self-paced performance was affected by the diazepam especially in letter matches by name. 4. This supported Mirsky and Kornetsky's conclusion (1964) rather than Frowein and Sanders (1978) recent findings.

Adolescent↗