Effet à court et long terme de la lecture sur les connexions du cerveau

Bernsgregory S., Prietulamichael J., Blainekristina, And Pyebrandon E.

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• Publié par: ActuaLitte.com
• Publié le: 29 décembre 2013
• Nombre de lectures: 1 608
• Langue: English
• Poids de l'ouvrage: 1 Mo

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BRAIN CONNECTIVITY
Volume 3, Number 6, 2013
ª Mary Ann Liebert, Inc.
DOI: 10.1089/brain.2013.0166
Short- and Long-Term Effects of a Novel
on Connectivity in the Brain
1 1 2 1Gregory S. Berns, Kristina Blaine, Michael J. Prietula, and Brandon E. Pye
Abstract
We sought to determine whether reading a novel causes measurable changes in resting-state connectivity of the
brain and how long these changes persist. Incorporating a within-subjects design, participants received resting-
state functional magnetic resonance imaging scans on 19 consecutive days. First, baseline resting state data for a
‘‘washin’’ period were taken for each participant for 5 days. For the next 9 days, participants read 1/9th of a novel
during the evening and resting-state data were taken the next morning. Finally, resting-state data for a ‘‘wash-
out’’ period were taken for 5 days after the conclusion of the novel. On the days after the reading, significant in-
creases in connectivity were centered on hubs in the left angular/supramarginal gyri and right posterior temporal
gyri. These hubs corresponded to regions previously associated with perspective taking and story comprehen-
sion, and the changes exhibited a timecourse that decayed rapidly after the completion of the novel. Long-
term changes in connectivity, which persisted for several days after the reading, were observed in bilateral
somatosensory cortex, suggesting a potential mechanism for ‘‘embodied semantics.’’
Key words: connectivity; fMRI; reading; resting state
A great book should leave you with many experiences, and guistic and literary theories describe what constitutes a
slightly exhausted at the end. You live several lives while reading. story, neurobiological research has just begun to elucidate
– William Styron, Conversations with William Styron. brain networks that are active when processing stories. To
date, these studies have focused on the immediate response
ostpeoplecan identify books that have made great im- to short stories (Mar, 2011). In other words, current neuro-Mpressions on them and, subjectively, changed the way biological theory of stories describes the network of brain
they think. Some can even point to a book that has changed regions that is active and presumably responsible for cogni-
their life. Stephen King, for example, said that Lord of the Flies tive processing of stories while they are being consumed.
changed his life, ‘‘because it is both a story with a message While active tasks have traditionally been used to iden-
and because it is a great tale of adventure.’’ Joyce Carol Oates tify functional networks within the brain, resting-state
pointed toAliceinWonderland as ‘‘the book that most influenced fMRI has become a common tool to identify consistent pat-
her imaginative life.’’ It seems plausible that if something as sim- terns of correlated activity, termed resting-state networks
ple as a book can leave the impression that one’s life has been (RSNs) (Biswal et al., 1995, 2010; Kelly et al., 2012; Raichle
changed, then perhaps it is powerful enough to cause changes et al., 2001).
in brain function and structure. Here, we test this possibility by Cognitive and emotional interventions have been demon-
using functional magnetic resonance imaging (fMRI) to track strated to cause transient changes in functional connectivity
changes in resting-state brain activity on a daily basis over a pe- (Harrison et al., 2008; Hasson et al., 2009; Mackey et al.,
riod of 3 weeks, during which individuals read a complete novel. 2013; Stevens et al., 2010), but it is not known how long
Novels are stories, and stories are complicated objects these changes last. Some changes appear to be due to tran-
of communication (Abbott, 2008).* Although several lin- sient activation of specific regions, which persists for minutes
to hours (Hasson et al., 2009); while others may persist
*‘‘Story’’ and ‘‘narrative’’ are often used interchangeably. Technically, for longer periods of time and may represent cortical reorga-
narrative (vs. expository text) is the representation of events, consisting nization (Mackey et al., 2013). A limitation of these studies
of a story (as a sequence of events, participating characters, and causal that makes it difficult to determine what are short- and
associations linking acts) and discourse (how the story is physically
long-term changes is the small number of resting-state scansconveyed). Thus, all conveyed stories are mediated by a narrative
4discourse (e.g., voice, text, video, actors). actually performed.
1
Department of Economics, Center for Neuropolicy, Emory University, Atlanta, Georgia.
2
Goizueta Business School, Emory University, Atlanta, Georgia.
590EFFECTS OF NOVEL ON BRAIN CONNECTIVITY 591
FIG. 1. Design of experiment (above). Participants underwent resting-state functional magnetic resonance imaging scans on
19 consecutive days (black arrows). On the evening before the middle 9 days of scanning, participants read a portion of the
novel, Pompeii. The mean arousal rating across participants (below) showed a rising trend toward the climax of the novel
(error bars– 1 standard error).
To determine a timescale over which connectivity changes Materials and Methods
persist, we measured changes in resting-state connectivity
Participants
as a result of reading a novel. We chose a novel over a
short story because the length and depth of the novel A total of 21 participants were studied. Two were excluded
would afford a set of repeated engagements with associated, from the fMRI analyses: one for insufficient attendance, and
unique stimuli (sections of the novel) set in a broader, con- the other for image abnormalities. Before the experiment, par-
trolled stimulus context that could be consumed between ticipants were screened for the presence of medical and psy-
several scanning periods. A within-subjects design was se- chiatric diagnoses, and none were taking medications. There
lected for this pilot study because of its substantive control were 12 female and 9 male participants between the ages of 19
of individual variability, statistical power, and economic ad- and 27 (mean 21.5). Emory University’s Institutional Review
vantages in this type of study (Anderson, 2001; Shadish Board approved all procedures, and all participants gave
et al., 2002). written informed consent.592 BERNS ET AL.
Reading material Scanning
Each participant was subject to 19 consecutive days ( July The scanning was performed on a Siemens 3T Trio. Each
18, 2011–August 5, 2011) of resting-state scans that consisted participant received only one T1-weighted structural image
of a total appointment time of less than 30 min at the same (TR= 2600 ms, TE= 3.93 ms, flip angle= 8, 224· 256 matrix,
time each day. The first 5 days and last 5 days were ‘‘wash- 176 sagittal slices, and 1 mm cubic voxel size) throughout
in’’ and ‘‘washout’’ sessions, respectively. Each of the middle the duration of the experiment. One functional resting-state
9 scans was preceded by reading approximately 1/9th of the scan was acquired each day (223 volumes, TR= 2000 ms, TE=
novel (Pompeii:ANovel, by Robert Harris, Fawcett, 2003). This 30 ms, flip angle= 73, FOV= 192 mm, 64· 64 matrix, 33 axial
novel was chosen because it was based on true events but slices, and 3· 3· 3.5 mm resolution with an added 10% gap in
written as historical fiction and conveyed in a classic narra- the z-direction, resulting in a resolution of 3· 3· 3.85 mm).
tive arc (Freytag, 1900). During the ‘‘washin’’ and ‘‘wash- Participants were instructed to rest quietly with eyes closed.
out’’ sessions, the participants did not perform any other
tasks except for the resting-state scan (Fig. 1). For each of
Preprocessing
the other 9 days, the story days, the participants performed
the resting-state scan after taking a quiz and self-report All of the preprocessing was performed using the 1000
about the effect of the material presented in the portion of Functional Connectomes Scripts available from NITRC
the novel that was assigned for the previous night and in- (www.nitrc.org). The only modification to these scripts was
cluded a five-point rating scale of how arousing the reading the addition of an iterative loop to cycle through the 19days
was (see Supplementary Data for quizzes; Supplementary of data. The scripts performed the following preprocessing
Data are available online at www.liebertpub.com/brain). procedures using FSL (Analysis Group, FMRIB) and AFNI
Through repeated scans, each participant served as his or (NIMH). First, the anatomical image was deobliqued and
her own control to measure changes in resting-state connec- reorientated to the coordinate space that is compatible with
tivity after the consumption of the novel. FSL. Next, the image was skull stripped.
Table 1. Washout Versus Washin Connections
Node MNI Label Node MNI Label
Washout> washin (p= 0.022)
120 66015 L cerebellum 131 346729 L cerebellum
130 16624 Cerebellar vermis 131 346729 L cerebellum
109 245421 L 140 337330 R
109 245421 L cerebellum 150 217933 L
120 66015 L 150 217933 L cerebellu