Biomedical subjects

Brian McElree

Publications and source records attributed to Brian McElree.

5 recordsLinked to original sources

PubMed2006

Attention speeds processing across eccentricity: feature and conjunction searches.

We investigated whether the effect of covert attention on information accrual varies with eccentricity (4 degrees vs 9 degrees) and the complexity of the visual search task (feature vs conjunction). We used speed-accuracy tradeoff procedures to derive conjoint measures of the speed of information processing and accuracy in each search task. Information processing was slower with more complex conjunction searches than with simpler feature searches, and overall it was faster at peripheral (9 degrees) than parafoveal (4 degrees) locations in both search types. Covert attention increased discriminability and accelerated information accrual at both eccentricities, and the magnitude of this attentional effect was the same for both feature (simple) and conjunction (complex) searches. Interestingly, in contrast to the compensatory effect of covert attention on information processing at iso-eccentric locations (temporal performance fields), covert attention did not eliminate speed differences across eccentricity.

Attention↗

PubMed2006

A time course analysis of enriched composition.

Linguistic analyses suggest that common and seemingly simple expressions, such as began the book, cannot be interpreted with simple compositional processes; rather, they require enriched composition to provide an interpretation, such as began reading the book (Jackendoff, 1997; Pustejovsky, 1995). Recent reading time studies have supported these accounts by providing evidence that these expressions are more costly to process than are minimally contrasting controls (e.g., McElree, Traxler, Pickering, Seely, and Jackendoff, 2001). We report a response signal speed-accuracy trade-off (SAT) study in which two types of expressions that are thought to require enriched composition were examined. Analyses of the full time course SAT data indicate that these expressions were interpreted less accurately and, most importantly, more slowly than control sentences. The latter finding suggests that enriched composition requires the online deployment of complex compositional operations.

Comprehension↗

PubMed2005

The difficulty of coercion: a response to de Almeida.

The sentence The secretary began the memo requires specifying what event the secretary began, because the memo does not refer to an event. McElree, Traxler, Pickering, Seely, and Jackendoff (2001) and Traxler, Pickering, and McElree (2002) found evidence from both self-paced reading and eye-tracking that such sentences caused processing difficulty, and thus argued that people "coerced" the object to refer to an event (e.g., writing the memo). de Almeida (2004) reports two self-paced reading experiments that failed to replicate some aspects of previous studies, and thereby argued against coercion during comprehension. A new experiment demonstrates coercion costs using new items, and provides evidence of coercion cost with de Almeida's stimuli. We conclude that coercion does cause processing difficulty.

Cognition↗

PubMed2004

Temporal performance fields: visual and attentional factors.

This study is the first to investigate: (a) 'temporal performance fields,' whether the speed of information accrual differs for different locations at a fixed eccentricity, and (b) whether covert attention modulates temporal dynamics differentially at isoeccentric locations. Using the speed accuracy tradeoff (SAT) procedure, we derived conjoint measures of how isoeccentric locations and precueing targets location affect speed and accuracy in a search task. The results demonstrate the existence of temporal performance fields, analogous to spatial performance fields: information accrual was fastest for target on the horizontal meridian, intermediate for targets at the intercardinal locations, slow for targets on the vertical meridian, and slowest for targets at the North (N) location (accrual time pattern: E&W S>intercardinal>E&W). Hence, the compensatory effect of attention eliminated the temporal asymmetries across isoeccentric locations.

Attention↗

PubMed2003

Speed of visual processing increases with eccentricity.

The visual system has a duplex design to meet conflicting environmental demands: the fovea has the resolution required to process fine spatial information, but the periphery is more sensitive to temporal properties. To investigate whether the periphery's sensitivity is partly due to the speed with which information is processed, we measured the full timecourse of visual information processing by deriving joint measures of discriminability and speed, and found that speed of information processing varies with eccentricity: processing was faster when same-size stimuli appeared at 9 degrees than 4 degrees eccentricity, and this difference was attenuated when the 9 degrees stimuli were magnified to equate cortical representation size. At the same eccentricity, larger stimuli are processed more slowly. These temporal differences are greater than expected from neurophysiological constraints.

Differential Threshold↗