Authors

Kim JJ. Andreasen NC. O'Leary DS. Wiser AK. Ponto LL.

Watkins GL. Hichwa RD.

 

Institution

Mental Health Clinical Research Center, University of Iowa, College of Medicine, Iowa City, Iowa, USA.

Title

Direct comparison of the neural substrates of recognition memory for words and faces.

 

Source

Brain. 122 ( Pt 6):1069-83, 1999 Jun.

 

Abstract

For the purpose of identifying the relatively specific brain regions related

to word and face recognition memory on the one hand and the regions common to

both on the other, regional cerebral blood flow associated with different

cognitive tasks for recognition memory was examined using [H215O]PET in

healthy volunteers. The tasks consisted of recognizing two types of stimuli

(faces and words) in two conditions (novel and familiar), and two baseline

tasks (reading words and gender classification). The statistical analyses

used to identify the specific regions consisted of three subtractions: novel

words minus novel faces, familiar words minus familiar faces, and reading

words minus gender classification. These analyses revealed relative

differences in the brain circuitry used for recognizing words and for

recognizing faces within a defined level of familiarity. In order to find the

regions common to both face and word recognition, overlapping areas in four

subtractions (novel words minus reading words, novel faces minus gender

classification, familiar words minus reading words, and familiar faces minus

gender classification) were identified. The results showed that the

activation sites in word recognition tended to be lateralized to the left

hemisphere and distributed as numerous small loci, and particularly included

the posterior portion of the left middle and inferior temporal gyri. These

regions may be related to lexical retrieval during written word recognition.

In contrast, the activated regions for face recognition tended to be

lateralized to the right hemisphere and located in a large aggregated area,

including the right lingual and fusiform gyri. These findings suggest that

strikingly different neural pathways are engaged during recognition memory

for words and for faces, in which a critical role in discrimination is played

by semantic cueing and perceptual loading, respectively. In addition, the

investigation of the regions common to word and face recognition indicates

that the anterior and posterior cingulate have dissociable functions in

recognition memory that vary with familiarity, and that the cerebellum may

serve as the co-ordinator of all four types of recognition memory processes.