Creativity & Schizophrenia
Antonio Preti
SOME
KINDS OF LIFE
The
style of thought of schizophrenic patients is influenced by their particular way
of filtering and organizing information. Yet Kraepelin, describing the syndrome
which Bleuler later called “schizophrenia”, noted that his patients showed
evident disorder of attention, an observation confirmed by Bleuler. In the 1960s
McGhie and Chapman (1961) observed, with appropriate tests, important deficits
in the systems involved in the gating of inputs. From these deficits derive the
patients‘ difficulties in selecting between environmental stimuli. In their
words: «if gating is defective, inhibition and selectivity fail and
consciousness is floaded with an undifferentiated and involuntary tide of
sensory data sweeping away the stable construct of reality».
Even
normal individuals, when subjected to an overload of stimuli, show mental
associations of a psychotic type, with hallucinations and delusions, just like
individuals under the influence of psychedelic drugs (LSD, for example) (a
review in Hoffer and Osmond, 1967). The deficits of attention in schizophrenia
are confirmed by electrophysiological studies, like the study of the evoked
potentials and the study of the acoustic startle reflex (Baribeau-Braun et al,
1983; Posner et al, 1988; Braff and Geyer, 1990; Perry and Braff, 1994;
Cornblatt and Kellp, 1994). What appears characteristic of the schizophrenic
patients is their difficult to narrow the flow of information (McGhie and
Chapman, 1961; Baribeau-Braun et al, 1983; Braff and Geyer, 1990; Cornblatt and
Kellp, 1994). As a consequence, as stated by Bleuler, these patients are «incapable
of holding the train of thought in the proper channel».
The
deficits of attention appear lateralized in some circumstances, with an apparent
specific involvement of the left hemisphere (Flor-Henry, 1983; Early et al,
1986; Posner et al, 1988). However, the performance of schizophrenic patients in
well selected neuropsychological tests shows that the cognitive impairment in
schizophrenia is not specifically localized, but is instead present in both
hemispheres (Blanchard and Neale, 1994). The main alteration consists in
abnormal information-processing, deriving from the patients’ difficulties to
discriminate between environmental stimuli and stimuli coming from his or her
inner world (Braff and Geyer, 1990; Preti, 1995).
The
overload leads to abnormal induction of associative inputs from the memory data
bank of the cortical areas, with consequent production of unusual interrelations
among very different sets of inputs. The interpretation of the patient of these
unusuallly linked stimuli, evoked by perceptions which would usually be
inhibited, produces narrative constructs which, when verbally expressed, are
often considered delusional by people who do not share the experiences of the
patient (Maher, 1992; Bovet and Parnas, 1993; Manschreck, 1995).
This
difficulty in processing information has dramatic consequences. The mantaining
of an adequate social communicative exchange depends on the correct evaluation
of contextual environmental stimuli. Patients are often unable to evaluate
relational inputs properly: the quality of their social intercourse is damaged,
with a further increase of stress. Problem in beginning and mantaining
communicative exchange often exarcerbate the patients’ symptoms.
Individuals subject to this form of social stress tend to progressively avoid
any interpersonal contact, withdrawing into the autistic world (Wing, 1978;
Fowles, 1992).