Quarterly Journal of Experimental Psychology

Orienting to a target by looking and pointing is examined for parallels between the control of the two systems and interactions due to movement of the eyes and limb to the same target. Parallels appear early in orienting and may be due to common processing of spatial information for the ocular and manual systems. The eyes and limb both have shorter response latency to central visual and peripheral auditory targets. Each movement also has shorter latency and duration when the target presentation is short enough (200 msec) that no analysis of feedback of the target position is possible during the movement. Interactions appear at many stages of information processing for movement. Latency of ocular movement is much longer when the subject also points, and the eye and limb movement latencies are highly correlated for orienting to auditory targets. Final position of eyes and limb are significantly correlated only when target duration is short (200 msec). This illustrates that sensory information obtained before the movement begins is an important, but not the only, source of input about target position. Additional information that assists orienting may be passed from one system to another, since visual information gained by looking aided pointing to lights and proprioceptive information from the pointing hand seemed to assist the eyes in looking to sounds. Thus the production of this simple set of movements may be partly described by a cascade-type process of parallel analysis of spatial information for eye and hand control, but is also, later in the movement, assisted by cross-system interaction.

Subjects were presented with lists of 'compound letters,’ letters whose overall shapes were described by repeated use of replicates of other, smaller letters. In Experiment 1 subjects were asked to attend to either the overall letter or the smaller, constituent letter. At the end of list presentation, recall of all letters was required, but a postlist cue determined whether the attended or unattended letters were to be reported first. The results for four-item lists accorded with those of Martin (1978, 1980): order of report had a larger effect upon retention of attended letters than upon retention of unattended letters. The findings for three-item lists did not agree with Martin, however: first, the interaction of attention and order was weak; second, sharp recency for unattended letters was not found.

Experiment 2 required that subjects recall either in temporal pairs or by letter size. The results strongly suggest that the present paradigm does not constitute an analogue to dichotic listening. In particular, there is little evidence for a role for sensory retention of compound letters at time of recall.

Previous research has shown that subjects can make up sentences faster from related noun pairs than from unrelated pairs. Two experiments tested the proposal that for the related pairs a subject simply has to access stored information but must make up an appropriate relation for unrelated pairs. In both studies the subjects were asked on some trials to remember a digit preload while they made up their sentences. Contrary to an initial prediction, the latencies were faster rather than slower with a preload. Furthermore, a surprise recall test at the end of Experiment 2 showed that there was no difference in the recall of related and unrelated pairs. The results were interpreted as evidence that semantic work was necessary for both types of noun pairs, and that the subjects did less semantic work with a digit preload. This interpretation was further supported by the finding that with the preload the subjects produced a narrower range of semantic relations between the noun pairs.

Signal detection theory and choice theory are sufficiently similar in their predictions to make it difficult to decide which gives the better fit to experimental data. In some cases, such as the analysis of word recognition, this similarity has allowed choice theory formulations to be employed as approximations to those given by signal detection theory. It could be proposed that signal detection theory gives the more valid description of the underlying processes, and choice theory provides an approximation to it; or one might choose to argue the reverse. A procedure for testing between choice theory and signal detection theory is described and is applied to the data of Miller, Heise and Lichten (1951) and to the results of an experiment. Both sets of results favour signal detection theory rather than choice theory.

Three experiments were conducted to determine how variables other than movement time influence the speed of visual feedback utilization in a target-pointing task. In Experiment 1, subjects moved a stylus to a target 20 cm away with movement times of approximately 225 msec. Visual feedback was manipulated by leaving the room lights on over the whole course of the movement or extinguishing the lights upon movement initiation, while prior knowledge about feedback availability was manipulated by blocking or randomizing feedback. Subjects exhibited less radial error in the lights-on/blocked condition than in the other three conditions. In Experiment 2, when subjects were forced to use vision by a laterally displacing prism, it was found that they benefited from the presence of visual feedback regardless of feedback uncertainty even when moving very rapidly (e.g. less than 190 msec). In Experiment 3, subjects pointed with and without a prism over a wide variety of movement times. Subjects benefited from vision much earlier in the prism condition. Subjects seem able to use vision rapidly to modify aiming movements but may do so only when the visual information is predictably available and/or yields an error large enough to detect early enough to correct.

With single-item visual displays, facilitating effects of foreknowledge of position have been shown in detection tasks with latency and with accuracy as the dependent variables, as well as in recognition tasks with latency as the dependent variable. There is no evidence, however, of positive selective attention effects on recognition accuracy with single-item displays. One failure to find such an effect was reported by Grindley and Townsend (1968). It is argued that in the study of Grindley and Townsend sub-optimal conditions were used and that a more elaborate replication of their study is in order. In the experiment reported here, an exposure duration resulting in 75% correct recognitions of target letters was determined per subject. This exposure time was used in the subsequent experimental sessions. In the experimental trials, single letters were presented on one out of five positions on an imaginary circle around a fixation point. The position of the impending target item was either cued or not cued by presenting either one or five dots at corresponding positions on the circumference of a similar, but somewhat larger, imaginary circle. The results showed a small, but highly significant, improvement in recognition accuracy when the position of the target letter was cued. It is concluded that cueing enhances recognition accuracy in single-item displays. Such an effect can only be shown if optimal experimental conditions are used.

This paper describes some aspects of reading and writing in a highly literate subject who has unusual difficulty in reading and spelling non-words. No cerebral trauma is indicated, and she performs at above average levels on standard tests of reading, spelling and cognitive ability. Only digit span is significantly impaired. Although auditory phoneme discrimination is normal, she performs poorly on aural tasks, like rhyme judgement and homophone matching, that require awareness of phonemic structure, and she is impaired at segmenting heard words into their component sounds.

Tests of immediate memory confirm abnormal span and indicate a failure to use normal phonological coding in immediate recall. We argue that a deficit in phonological processing underlies impaired performance on tasks of reading, spelling and immediate memory.

Responses to items such as brane are slower and/or more error prone than responses to items such as slint in lexical decision (is this string spelt like a real word?). The received view is that this “pseudohomophone” effect is attributable to phonological receding. Taft (1982) has challenged this view, offering instead a grapheme-grapheme account which assumes that graphemes that map onto a common phoneme develop the ability to activate each other without reference to phonological mediation.

Taft's grapheme-grapheme account is tested in two experiments. Experiment 1 shows that the presentation of a pseudohomophone facilitates the response to a subsequently presented word (e.g., groce–gross). Experiment 2 shows that nonword letter strings that are translatable into words by the application of putative grapheme-grapheme rules (e.g., gloce–gloss) produce no facilitation. These results are consistent with the notion of a phonological influence but inconsistent with the grapheme–grapheme account. Loci for this pseudohomophone priming effect are discussed.