Biomedical subjects

E McKone

Publications and source records attributed to E McKone.

6 recordsLinked to original sources

PubMed2001

Categorical perception of face identity in noise isolates configural processing.

Neuropsychological evidence suggests that face recognition based on configural (holistic) information can occur in isolation from recognition based on local feature cues. The present study shows that configural processing can be isolated experimentally in normal subjects. A phenomenon is reported that exists only for upright whole faces, namely categorical perception (CP) of face identity in noise. Three discrimination tasks (ABX, better likeness, and similarity ratings) were used to test for perceptual distortion across the category boundary predicted from binary classification of face morphs. Noise was added such that any single local region provided unreliable cues to identity. Under these conditions, CP was found for upright faces but not for inverted faces or single features, even with more than 10,000 trials. The CP-in-noise signature phenomenon was then used to show that configural processing survives image plane rotations of 45 degrees-90 degrees.

Adult↗

PubMed2000

Short-term implicit memory: visual, auditory, and cross-modality priming.

Short-term implicit memory was examined for mixed auditory (A) and visual (V) stimuli. In lexical decision, words and nonwords were repeated at lags of 0, 1, 3, and 6 intervening trials, in four prime-target combinations (VV, VA, AV, AA). Same-modality repetition priming showed a lag x lexicality interaction for visual stimuli (nonwords decayed faster), but not for auditory stimuli (longer lasting smooth decay for both words and nonwords). These modality differences suggest that short-term priming has a perceptual locus, with the phonological lexicon maintaining stimuli active longer than the orthographic lexicon and treating pseudowords as potential words. We interpret these differences in terms of the different memory needs of speech recognition and text reading. Weak cross-modality short-term priming was present for words and nonwords, indicating recoding between perceptual forms.

Adult↗

PubMed1999

Acquisition of novel traces in short-term implicit memory: priming for nonwords and new associations.

McKone (1995) reported a short-lived repetition priming effect (up to 8 sec and three intervening items), superimposed on long-term priming. In lexical decision and naming, decay of this short-term implicit memory was faster for pseudowords than for words, suggesting an explanation in terms of transient activation of preexisting lexical representations. Here, we present two cases where, in contrast, preexperimental familiarity did not affect short-term priming, indicating acquisition of novel traces. Experiment 1 determined repetition priming in same-different judgments to lowercase-uppercase pairs for words, and for nonwords with three levels of wordlikeness. Across lags of 0, 1, and 6 intervening items (2-14 sec), short-term priming was the same for all stimuli, even random letter strings. Experiments 2 and 3 assessed priming in a double lexical decision task for old associations (orange-apple) and new associations (cigar-errand). Short-term priming for the association was equal in both cases.

Adult↗

PubMed1999

Orientation invariance in naming rotated objects: individual differences and repetition priming.

In naming drawings of complex common objects, unpracticed naming times increase with rotation away from the upright, but this orientation effect is attenuated with practice. In principle, attenuation could result from learning to extract orientation-invariant information or from learning view-specific representations at the trained orientations. We contrasted these approaches by examining repetition priming for prime-target pairs presented on successive trials in either the same orientation (horse at 51 degrees primes horse at 51 degrees) or a different orientation (horse at 154 degrees primes horse at 51 degrees), for two subgroups of subjects. One subgroup showed no orientation effect, even when unpracticed, and a correspondingly high generalization of priming across different views. The other subgroup initially showed high sensitivity to misorientation and little priming across orientations but, with sufficient practice, came to show no orientation effect and complete generalization of priming. Thus, some subjects always used orientation-invariant procedures, whereas others learned to do so.

Adult↗

PubMed1998

The decay of short-term implicit memory: unpacking lag.

McKone (1995) reported a short-lived repetition priming effect, superimposed on long-lived priming. This short-term implicit memory survived a few intervening items and several seconds for words but decayed precipitously for nonwords, producing a lag x lexicality interaction. Here, mechanisms of decay are studied by disconfounding the time delay and interference components of lag. In Experiment 1, time delay was varied while number of intervening items was held constant, and vice versa. In Experiment 2, priming was plotted as a function of time delay, with and without intervening items. Using a lexical decision task, both experiments found independent contributions of time and interference to the decay of short-term priming. Further, Experiment 2 attributed the lag x lexicality interaction to a particular sensitivity of nonword traces to interference. An illustration of how these effects might arise in the word recognition system is provided.

Adult↗

PubMed1997

Explicit contamination in "implicit" memory for new associations.

In one view of implicit memory, priming arises from modification of preexisting representations; however, the role of such representations is currently in doubt following findings of implicit memory for newly formed associations. Closer consideration of studies reporting this effect, and of others that have failed to obtain it, suggests that such priming might results from the employment of explicit memory strategies. With measures designed to permit exclusion of such strategies, three experiments using lexical decision and stem-completion tasks found no evidence of truly implicit memory for unrelated pairs. Instead, priming was found only in those subjects (50% of the total in one experiment) who reported using explicit memory in stem completion. Contrary to previous conclusions, the results indicate a role for established representations in explaining implicit memory.

Adult↗