Hockenbury Discovering Psychology 5th txtbk

Introduction: Thinking, Language, and Intelligence279FOCUS ON NEUROSCIENCESeeing Faces and Places in the Mind’s EyeUntil the advent of sophisticated brain-scanning techniques,studying mental imagery relied on cognitive tasks, such as measuringhow long participants reported it took to scan a mentalimage (see Kosslyn & others, 2001). Today, however, psychologistsare using brain-imaging techniques to study mentalimagery. One important issue is whether mental images activatethe same brain areas that are involved in perception. Remember,perception takes place when the brain registers informationthat is received directly from sensory organs.Previously, researchers have found that perceiving certain typesof scenes or objects activates specific brain areas. For example,when we look at faces, a brain area dubbed the fusiform facialarea (FFA) is activated. When we look at pictures of places, adifferent brain area, called the parahippocampal place area, orPPA, is activated (Epstein & Kanwisher, 1998; Kanwisher, 2001).Given these findings, the critical question is this: If we simplyimagine faces or places, will the same brain areas be activated?To answer that question, psychologists Kathleen O’Craven andNancy Kanwisher (2000) used functional magnetic resonanceimaging (fMRI) to compare brain activity during perception andimagery. Study participants underwent fMRI scans while theylooked at photographs of familiar faces and places (scenes fromtheir college campus). Next, the participants were asked to closetheir eyes and form a vivid mental image of each of the photographsthey had just viewed.Three key findings emerged from the study. First, as you can seefrom the fMRI scans of two participants shown here, imagininga face or place activated the same brain region that is activatedwhen perceiving a face or a place. More specifically, forming amental image of a place activated the parahippocampal placearea. And, forming a mental image of a face activated thefusiform facial area.Second, compared to imagining a face or place, actually perceivinga face or place evoked a stronger brain response, as indicatedby the slightly larger red and yellow areas in the perceptionfMRIs (upper row). Third, because the brain responses betweenthe two conditions were so distinctive, O’Craven and Kanwishercould determine what the participants were imagining—faces orplaces—simply from looking at the fMRI scans.Other neuroscientists have confirmed that there is considerableoverlap in the brain areas involved in visual perception andmental images (Ganis & others, 2004). Clearly, perception andimagination share common brain mechanisms. So, at least as faras the brain is concerned, “the next best thing to being there”might just be closing your eyes . . . and going there in yourmind’s eye.FACESubject 1 Subject 2perceptionperceptionimageryimageryPLACESubject 1 Subject 2perceptionperceptionimageryimageryBrain Activation DuringPerception and MentalImagery Shown hereare the fMRIs of twoparticipants in O’Cravenand Kanwisher’s (2000)study. Notice that thesame brain areas are activatedwhile perceivingor imagining a familiarface. Likewise, the samebrain areas are activatedwhile perceiving orimagining a familiarplace. Also notice thatthe brain activation isslightly stronger in theperception conditionthan in the mentalimagery condition.Adding to the efficiency of our thinking is our tendency to organize the conceptswe hold into orderly hierarchies composed of main categories and subcategories(Markman & Gentner, 2001). Thus, a very general concept, such as “furniture,”can be mentally divided into a variety of subcategories: tables, chairs, lamps, and soforth. As we learn the key properties that define general concepts, we also learn howmembers of the concept are related to one another.How are concepts formed? When we form a concept by learning the rules orfeatures that define the particular concept, it is called a formal concept. Childrenare taught the specific rules or features that define many simple formal concepts,conceptA mental category of objects or ideas basedon properties they share.formal conceptA mental category that is formed by learningthe rules or features that define it.