Neurophysiological evidence of impaired attention and working memory in untreated hematologic cancer patients

Abstract

Objective: Neuroimaging studies of hematologic cancer patients report altered activity in dorsal attention and central executive networks. To determine the consequences of these altered brain networks, we evaluated neurophysiological correlates of attention and working memory in hematologic cancer patients prior to initiating treatment.

Methods: Hematologic cancer patients (19-80 years) were excluded for premorbid cognitive impairment, prior non-hematologic cancer diagnosis, and prior chemotherapy. Attention was manipulated by presenting an irrelevant spatial cue prior to visual search displays. Working memory was manipulated by presenting irrelevant distractors within memory displays. Electroencephalogram was recorded during task performance.

Results: Patients (n = 28) and controls (n = 15) were balanced on age, gender, and education. Spatial cues evoked larger N2pc amplitudes, a correlate of spatial attention, in patients than controls (p < .05; Cohen's d > 0.7). Memory distractors evoked larger contralateral delay activity amplitudes, a correlate of working memory load, in patients (p = .028; Cohen's d = 1.1) but not controls (p = .64).

Conclusions: Prior to initiating treatment, hematologic cancer patients demonstrated poor control over spatial attention and working memory, consistent with altered dorsal attention and central executive network activity.

Significance: Hematologic cancer patients may be at a higher risk for selecting, processing, and storing distracting information that would compete with more immediate goal-related behaviors.

Keywords: Attention; Cancer; Cognitive impairment; Electroencephalography; Hematologic cancer; Working memory.