Sustained attention in psychosis: Neuroimaging findings

Table 2 Functional magnetic resonance imaging studies of sustained attention in bipolar disorder

Ref.	Participants	Task and behavioral results	FMRI methods and results
Strakowski et al[69], 2004	BDI (n = 10), age 25.5 ± 8.1, males 40%, euthymic, age of onset 23 yr, illness duration 2.2 yr, medicated 0% (drug free)	CPT-IP. Type of stimuli: digits TNS = 400 SET = 700 ms, ISI = 750, TET = 6 min Required response: on targets. Behavioral measures: d’, percent correct, percent false positive	3T, block design, 5 task blocks and 5 baseline blocks Baseline: digits fixation Whole brain analysis. Imaging package: CHIPS
	NC (n = 10), age25.3 ± 7.3, males 40%	Results: no between-group differences	Results:BDI > NC in: R IFG/insula (BA 13/47), R and L ventral PFC (BA 10/47), parahippocampus/amygdala (BA 34), MOG/MTG (BA 18/19/39), R IPL (BA 40), R SPL (BA 7/40), L postcentral gyrus (BA 43), hypothalamus; NC > BDI in: L fusyform gyrus (BA 20) and L MFG (BA 11)
Fleck et al[70], 2012	BDI (n = 50), age 30 ± 10, males 30%, manic, medicated 80%	CPT-IP. Type of stimuli: digits TNS = 900, Target = 15%, SET = 750 ms, ISI = 1000 ms, TET = 15 min	4T, Event-related design, 3 runs (periods) Whole brain analysis. Imaging package: AFNI ROi based analysis: anterior-limbic network (IFG, BG, TH, amygdala, cerebellar vermis) + SFGBaseline: visual count down condition Task conditions: -hits, misses and false alarms -correct rejections on non-targets
	NC (n = 34), age 31 ± 9, males 41%	Required response: on targets Behavioral measures: A’, B’’, RT, correct rejectionResults: patients performed worse in terms of correct rejections and showed a trend vs a reduced A’	Results: In period 1: NC > BD in cerebellum; BD > NC in TH; NC > BD in deactivation of L PCC and R angular gyrusIn period 2: NC > BD in bilateral IFG and L THIn period 3: NC > BD in activation of R IFGOver time: BD activated and NC deactivated L striatum and bilateral amygdala Unmedicated BD > medicated BD in activation of R IFG and cerebellum
Sepede et al[71], 2012	BDI (n = 24), age 34.8 ± 8.0, males 41.7%, euthymic, age of onset 29.9, illness duration 4.7 yr, psychotic features during acute phases 95.8%, medicated 83.3%	CPT-X with 2 levels of difficulty: undegraded and degraded stimuli (0% and 40% pixel inverted)Type of stimuli: digits TNT = 80, Target = 20%, TNS = 408 ± 30 SET = 200 ms, ISI = 2000 ms, TET = 14 min	1.5T, event-related design, 2 runs (0%, and 40% degraded). Whole brain analysis. Imaging package: BrainVoyager QX 1.9.Task conditions: -correct responses on target -incorrect responses on target -correct responses on non-targets (baseline)
	REL-BDI (n = 22), age 31.5 ± 7.3, males 31.8% medicated 0% (drug naïve)	Required response: on targets and non-targets Behavioral measures: correct target, correct non-targets, incorrect target, incorrect non-target, mean RT	ResultsCorrect target vs baseline: (NC = REL-BDI) > BDI in R insula (BA13) REL-BDI > (NC = BDI) in deactivating PCC/retrosplenial cortex (BA 23/29) During the 40% degraded run, correct target condition: REL-BDI > (NC = BDI) in R and L IPL (BA 40), L insula/IFG (BA 13/45)
	NC (n = 24), age 32.5 ± 6.2, males 33.3%	Results: both BDI and REL-BDI were less accurate than NC in target recognition (percent correct target )	Incorrect target vs baseline:(BDI = REL-BDI) > NC in middle PCC (BA 31) and R insula/IFG (BA 13/45)BDI > REL-BDI > NC in L insula (BA 13)

BDI: Bipolar disorder type I patients; REL-BDI: Unaffected relatives of bipolar disorder type I patients; NC: Normal comparisons; PFC: Prefrontal cortex; ACC: Anterior cingulate cortex; PCC: Posterior cingulate cortex; MFG: Medial frontal gyrus; SFG: Superior frontal gyrus; IFG: Inferior frontal gyrus; IPL: Inferior parietal lobule; SPL: Superior parietal lobule; MTG: Middle temporal gyrus; MOG: Middle occipital gyrus; TH: Thalamus; BG: Basal ganglia; R: Right; L: Left.