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Biomedical subjects

P C Dodwell

Publications and source records attributed to P C Dodwell.

7 recordsLinked to original sources
PubMed1978

Reaching in very young infants.

It has been claimed that reaching to visually presented targets is a valid indicator of perceptual capacity in very young infants. In a previous report we failed to replicate the findings on which that claim is based. Here we reanalyze some of the tapes of the first report, using a less restricted criterion for what constitutes a reach, and a much more detailed analysis of the various components of reaching behaviour. A number of components are readily distinguished and reliably observed. Infants of seven to twenty-one days show great individual variation in their reaching, from no such behaviour to a great deal. Certain clusters of the components of reaching can be used to define different reaching "styles". The infants who reached most frequently in our sample all showed a dominant pattern of reaching, which in certain respects appears to be more mature than that of other babies. The finer analysis revealed no differences in the reaching behaviour to objects and pictures of objects, even among the most active reachers.

Arm↗
PubMed1977

Pattern structure and relational discrimination learning.

McGonigle and Jones take exception to Dodwell's explanation of anomalous transfer (AT) as the outcome of relational discriminations among a set of stimulus patterns which vary along a single dimension of orientational salience, from 'horizontal' to 'vertical'. In particular they do not think that the continuum is generated by units with Hubel-and-Wiesel type retinal receptive fields. Instead, they invoke Garner's notions about stimulus structure to explain Dodwell's results, as well as their own finding of two situations where AT fails to occur. It seems that McGonigle and Jones missed the point of the relational discrimination explanation of AT. In fact, it is shown that AT is not predicted by this model for the conditions in which they failed to obtain it. The relational model makes definite predictions about conditions under which AT will occur; as this is not true of their invocation of Garner's ideas, the former is to be preferred. Whether or not outputs are coded by Hubel-and Wiesel type units is not particularly relevant to the main point, that AT is a result of relational learning. In fact, the model is an instance of how structure, in Garner's sense, can be generated.

Animals↗
PubMed1976

Responses of infants to visually presented objects.

The reaching behavior of some 60 infants between 7 and 23 days of age was studied. Contrary to some other reports, the infants did not respond differently to a visually presented, graspable, solid object than to its two-dimensional representation.

Child Behavior↗