The effects of lesions from basal ganglia and frontal lobe on working memory and learning ability

Abstract

Objective To explore the effects of basal ganglia lesion and frontal lobe lesion on working memory and learning ability. Method Twenty-eight patients with brain damage contained 12 cases of frontal lobe lesions, 8 cases of left basal ganglia lesions and 8 cases of right basal ganglia lesions. Ten cases without brain damage were used as control group. The working memory and learning ability of all objects were evaluated and trained by Tower of Hanoi(TOH)and Wisconsin Card Sorting Test(WCST). Results The scores before training in TOH and WCST in patients with frontal lobe lesion and basal ganglia lesions were significantly different from control group [(0.66±0.24 vs 0.93±0.09,t =0.28,P <0.05);(0.74±0.17 vs 0.93±0.09,t =0.19,P <0.05)]. The scores before training in trails to complete first category of WCST were significantly higher in patients with frontal lobe lesion than that in patients with basal ganglia lesions(22.67±15.03,9.69±4.77,t =4.10, P <0.05). The accuracy and scores in TOH after training were significantly higher than that before training in patients with basal ganglia lesions(0.91±0.11,0.74±0.17,t =0.07,P <0.05). The percent errors, percent perseverative responses and conceptual level responses in WCST after training were significantly improved in patients with basal ganglia lesions as compared with patients with frontal lobe lesion(0.35±0.15,0.53±0.17,t =0.06,P <0.05). The scores of TOH and percent perseverative responses of WCST after training also were significantly improved in patients with half basal ganglia lesions. Conclusion The basal ganglia lesions and frontal lobe lesions may decrease working memory, but half basal ganglia lesions still can retain learning ability. These results suggest that early cognitive rehabilitation is very important for patients with basal ganglia lesions. Key words: Frontal lobe lesion; Basal ganglia lesion; Working memory disorder; Learning disorder