Consequences of an inhibition deficit for word production and comprehension: Evidence from the semantic blocking paradigm

Abstract

We investigated the semantic blocking effect in picture naming and word-picture matching for two nonfluent aphasic patients who show evidence of a deficit in inhibiting verbal representations (M.L. and B.Q), one fluent aphasic patient (K.V.), and neurologically intact control participants. In two picture-naming tasks (Experiments 1A and 1B), M.L. and B.Q, relative to controls, showed a greatly exaggerated semantic blocking effect in naming latencies that increased dramatically across repeated presentations. On two corresponding word-picture matching tasks (Experiments 2A and 2B), both also showed an increasing semantic blocking effect, though the effects were not as large nor as consistent as those in naming. The fluent patient, K.V., showed a pattern like controls on both tasks. On an associated word-picture matching task, both M.L. and B.Q showed results paralleling those of controls. The contrast between the production and comprehension patterns for M.L. and B.Q. supports the conclusion that their exaggerated blocking effect in production arises during lexical rather than semantic selection. We postulate that M.L.'s (and potentially B.Q's) production effect is due to difficulties in postselection inhibition, which results in overactivation of lexical representations. This overactivation is likely to be one source of their nonfluency in spontaneous speech.

Selective inhibition and naming performance in semantic blocking, picture-word interference, and color–word Stroop tasks.

“…Instead, selective inhibition is also recruited when several responses are highly coactivated because they are part of a small response set or have recently been produced (as in semantic blocking). Though the current study is, to our knowledge, the first to demonstrate directly that selective inhibition can be involved in the absence of overt distractor stimuli that induce different degrees of conflict, the result fits in well with the observation of Biegler, Crowther, and Martin (2008) that patients with a deficit in inhibiting verbal representations showed a greatly exaggerated semantic blocking effect.…”

Efectos de la edad de adquisición de las palabras en denominación de imágenes en sujetos afásicos hablantes del español

“…En términos generales, los hallazgos de la presente investigación resultan consistentes con los de estudios previos en los que se halló evidencia acerca del efecto facilitador de la EdA temprana sobre la producción léxica en pacientes afásicos (Biegler et al, 2008;Brown & Watson, 1987;Carroll & White, 1973;Morrison et al, 1992). Es plausible, entonces, considerar que la recuperación de representaciones fonológicas constituye un punto crítico en el proceso y donde la condición de afasia produce un mayor efecto adverso.…”

The Effect of Combining Inhibitory Control and Errorless Naming Treatment on Word Retrieval Deficits in Patients with Aphasia: Design and Protocol of a Pilot Randomized Double-Blinded Clinical Trial

“…Past investigations have shown that individuals with aphasia, in addition to linguistic deficits, demonstrate some signs of IC impairments (13,22,23). In this regard, models of word production suggest successful lexical retrieval is dependent on the ability to limit interference from co-activated lexical-semantic representations (24).…”

“…Hence, the continuous need to inhibit these competitors results in a delay in word retrieval. Furthermore, during the congruent condition of the paradigm, non-fluent PWAs have shown higher SIE relative to neurologically healthy patients (13,15).…”

“…Word retrieval (WR) in PWA is often characterized by interference from the simultaneous activation of semantic and phonological items, which results in semantic paraphasia and phonological paraphasia (11). Some studies reported that IC problems and linguistic deficits are often coexist in PWA aphasia and lead to slower and less accurate lexical retrieval relative to healthy people (12,13).…”