Influence on Cognitive Performance

smoking฀ facilitates฀ processes฀ related฀ to฀ the฀ motor฀ output฀ aspects฀ of฀ working฀ memory.฀ During฀the฀12฀h฀enforced฀abstention฀from฀smoking,฀reaction฀times฀were฀delayed฀as฀also฀ found฀for฀non-smokers,฀with฀the฀result฀that฀nicotine฀may฀ultimately฀be฀assumed฀to฀promote฀ working฀memory฀ [20] . In฀contrast฀to฀smoking,฀nicotine฀4฀mg฀nicotine฀chewing฀gum฀inluences฀various฀EEG฀ components฀increased฀theta฀and฀alpha฀frequency,฀decreased฀delta฀power.฀However,฀nei- ther฀reaction฀times฀nor฀event-related฀brain฀potentials฀were฀changed,฀as฀has฀been฀reported฀ after฀cigarette฀smoking฀ [31] . The฀anxiolytic฀effects฀induced฀by฀smoking฀depend฀on฀the฀benign฀distraction฀of฀the฀smoker฀ [32] .฀Only฀those฀who฀smoked฀a฀cigarette฀with฀a฀high฀nicotine฀yield,฀paired฀with฀participation฀ in฀a฀distracting฀activity,฀experienced฀a฀reduction฀in฀anxiety.฀Those฀who฀smoked฀in฀the฀absence฀ of฀distraction฀even฀experienced฀an฀exacerbation฀of฀anxiety฀ [32] .฀These฀indings฀suggest฀that฀ nicotine฀–฀rather฀than฀the฀behavioural฀or฀sensory฀aspects฀of฀smoking฀–฀interacts฀with฀distrac- tion฀and฀leads฀to฀the฀alleviation฀of฀anxiety฀or฀apprehension฀ [32] .฀Under฀laboratory฀conditions,฀ in฀contrast,฀nicotine฀tends฀to฀display฀anxiogenic฀activity฀ [33] . Smokers’฀reactions฀to฀a฀lexical฀decision-making฀test฀decision฀as฀to฀whether฀or฀not฀a฀ sequence฀of฀letters฀represents฀a฀word฀were฀also฀faster฀and฀more฀complete฀than฀those฀of฀ placebo฀cigarette฀smokers฀ [34] .฀According฀to฀other฀data,฀while฀cigarette฀smoking฀has฀no฀ negative฀effect฀upon฀performance฀for฀simple฀perceptual฀tasks฀smoking฀was฀found฀to฀exert฀ measurable฀negative฀effects฀upon฀performance฀for฀more฀complex฀information฀processing฀ tasks฀ [35] .฀The฀residual฀effects฀of฀smoking฀consist฀primarily฀of฀retardation฀of฀cognitive฀ processes฀in฀older฀adults฀ [36] ,฀whereas฀this฀negative฀effect฀is฀not฀observed฀in฀ex-smokers฀ and฀non-smokers.฀In฀a฀comparison฀with฀placebo,฀visual฀information฀processing฀was฀also฀ increased฀under฀4฀mg฀nicotine฀gum฀and฀cigarette฀smoking,฀whereas฀self-reported฀feelings฀ of฀alertness฀and฀energy฀were฀assessed฀as฀higher฀while฀cigarette฀smoking฀than฀under฀4฀mg฀ nicotine฀gum฀ [37] . Memory฀list฀of฀20฀words฀was฀tested฀in฀smokers฀of฀cigarettes฀with฀different฀nicotine฀ yields.฀ Smokers฀ of฀ higher-yield฀ cigarette฀ brands฀ were฀ found฀ to฀ have฀ better฀ recall฀ than฀ smokers฀ of฀ lower-yield฀ brands฀ [38] .฀ When฀ performing฀ more฀ dificult฀ tasks,฀ adolescent฀ smokers฀altered฀their฀smoking฀behaviour฀by฀taking฀more฀puffs฀per฀cigarette฀and฀inhaling฀ more฀deeply.฀Women฀responded฀more฀than฀men฀to฀the฀concentration฀task฀ [39] .฀The฀effects฀ of฀smoking฀a฀low฀0.7฀mg฀and฀a฀middle฀nicotine฀yield฀1.3฀mg฀cigarette฀on฀learning฀and฀ retention฀were฀tested฀in฀undergraduate฀smokers฀ [40] .฀Both฀nicotine฀levels฀had฀an฀effect฀on฀ retention฀only,฀with฀task฀dificulty฀appearing฀to฀be฀of฀secondary฀relevance.฀Serial฀learning฀ data฀suggested฀that฀the฀effect฀is฀shown฀more฀on฀long-term฀than฀on฀short-term฀memory.

7.1.3 Intellectual Impairment in Childhood

Several฀studies฀indicate฀that฀intellectual฀development฀is฀impaired฀in฀children฀whose฀mothers฀ actively฀smoke฀during฀pregnancy฀and฀that฀this฀harmful฀effect฀is฀less฀pronounced฀in฀the฀chil- dren฀of฀passive฀smokers฀ [41,฀42] .฀Other฀confounding฀variables฀were฀also฀eliminated฀from฀the฀ psychological฀tests฀employed.฀Contradictory฀results฀have฀been฀found฀for฀cognitive฀and฀lan- guage฀ability฀ [43–45] .฀Children฀exposed฀to฀the฀harmful฀effects฀of฀tobacco฀smoke฀were฀found฀ to฀have฀more฀behavioural฀abnormalities฀ [43,฀46–50] ,฀namely,฀heightened฀aggressiveness฀ [21,฀ 46–49,฀51] ,฀and฀an฀increased฀tendency฀to฀drug฀and฀nicotine฀dependence฀ [47,฀50] .฀Secondly,฀ depressive฀and฀anxious฀reactions฀have฀been฀described,฀and฀this฀inding฀applies฀more฀to฀boys฀ than฀to฀girls฀ [41,฀48,฀51] .฀Naturally,฀the฀value฀of฀any฀conclusion฀regarding฀childhood฀behav- iour฀depends฀on฀the฀test฀selected฀Child฀Behaviour฀Check-List,฀Child฀Problem฀Behaviour฀ Index,฀Home฀Observation฀for฀Measurement฀of฀the฀Environment฀etc.฀ [50,฀51,฀54] .฀Two฀studies฀ have฀shown฀an฀increased฀frequency฀of฀ADHD฀in฀children฀whose฀mothers฀smoked฀during฀ pregnancy฀ [45,฀55] .฀Similarly,฀an฀increased฀prevalence฀of฀idiopathic฀mental฀retardation฀was฀ detected฀in฀children฀passively฀exposed฀to฀cigarette฀smoke฀during฀pregnancy฀and฀postnatally฀ OR฀=฀1.9;฀CI:฀1.0–3.4,฀compared฀with฀a฀non-exposed฀control฀group฀ [56] . According฀to฀a฀study฀published฀in฀1999,฀long-term฀nicotine฀consumption฀has฀been฀linked฀ with฀self-medicating฀efforts฀to฀cope฀with฀the฀effects฀of฀adverse฀childhood฀experiences;฀peo- ple฀exposed฀to฀highly฀adverse฀experiences฀in฀childhood฀will฀also฀be฀under฀increased฀stress฀in฀ adulthood฀ [57] .฀In฀a฀retrospective฀cohort฀study,฀a฀total฀of฀9,215฀adults฀with฀mean฀ages฀of฀55.3฀ years฀women฀and.฀58.1฀years฀men฀responded฀to฀a฀survey฀questionnaire฀to฀identify฀the฀ adverse฀experiences฀to฀which฀they฀had฀been฀exposed฀in฀childhood:฀emotional,฀physical฀and฀ sexual฀abuse;฀a฀battered฀mother;฀parental฀separation฀or฀divorce;฀and฀growing฀up฀with฀a฀sub- stance-abusing,฀mentally฀ill฀or฀incarcerated฀household฀member.฀In฀persons฀reporting฀ive฀or฀ more฀categories฀of฀adverse฀childhood฀experiences,฀the฀association฀with฀cigarette฀consump- tion฀was฀unequivocal:฀they฀had฀a฀5.4-fold฀higher฀risk฀of฀smoking฀initiation฀by฀the฀age฀of฀14฀ years;฀a฀3.1-fold฀higher฀risk฀of฀ever฀smoking฀at฀a฀later฀time;฀and฀a฀2.8-fold฀higher฀risk฀of฀still฀ being฀a฀smoker฀at฀the฀time฀of฀the฀survey฀ [57] .฀Primary฀prevention฀of฀these฀adverse฀childhood฀ experiences฀and฀speciic฀treatment฀for฀those฀affected฀could฀help฀to฀reduce฀smoking. Trinidad฀et฀al.฀examined฀interactions฀between฀emotional฀intelligence฀EI฀and฀smoking฀ risk฀factors฀on฀smoking฀intentions฀in฀adolescents฀ [58] .฀They฀deined฀EI฀as฀the฀ability฀to:฀ accurately฀perceive,฀appraise฀and฀express฀emotion;฀access฀andor฀generate฀feelings฀in฀facil- itating฀thought;฀understand฀emotion฀and฀emotional฀knowledge;฀and฀regulate฀emotions.฀EI฀ of฀416฀sixth฀graders฀53฀girls฀from฀middle฀schools฀in฀the฀Los฀Angeles฀area฀mean฀age฀=฀ 11.3฀years;฀32฀Latino,฀29฀AsianPaciic฀Islander,฀13฀white,฀19฀Multiethnic,฀6฀ Others฀was฀assessed฀with฀an฀abbreviated฀version฀of฀the฀Multifactor฀Emotional฀Intelligence฀ Scale,฀Adolescent฀Version฀MEIS.฀This฀was฀a฀competence-based฀measure฀assessing฀an฀ individual’s฀ability฀to฀perceive,฀understand฀and฀manage฀emotion.฀Logistic฀regression฀mod- els฀were฀it฀to฀test฀interactions฀between฀EI฀and฀ever฀trying฀cigarettes,฀hostility฀and฀per- ceived฀ability฀to฀refuse฀a฀cigarette฀from฀someone฀just฀met,฀on฀intentions฀to฀smoke฀in฀the฀ next฀ year.฀ The฀ scientists฀ found฀ that฀ high฀ EI฀ adolescents฀ were฀ more฀ likely฀ to฀ intend฀ to฀ smoke฀in฀the฀next฀year฀if฀they฀had฀previously฀experimented฀with฀smoking.฀Those฀with฀low฀ EI฀were฀more฀likely฀to฀intend฀to฀smoke฀if฀their฀perceived฀ability฀to฀refuse฀a฀cigarette฀offer฀ from฀a฀person฀they฀just฀met฀was฀low฀or฀hostility฀level฀was฀high.฀In฀conclusion,฀the฀study฀ indicated฀that฀EI฀interacts฀with฀risk฀factors฀to฀reduce฀smoking฀intentions,฀and฀contributes฀ evidence฀to฀a฀link฀between฀EI฀and฀smoking฀in฀adolescents฀ [58] . In฀examining฀the฀criminal฀behaviour฀of฀children฀whose฀mothers฀smoked฀during฀preg- nancy฀ [59,฀60] ,฀two฀large-scale฀studies฀have฀revealed฀a฀higher฀rate฀of฀criminal฀offences฀in฀ adulthood฀among฀such฀offsprings฀ [55] .฀In฀a฀cohort฀of฀5,636฀men,฀compared฀with฀the฀sons฀of฀ mothers฀who฀did฀not฀smoke,฀the฀sons฀of฀mothers฀who฀smoked฀during฀pregnancy฀had฀a฀more฀ than฀twofold฀risk฀of฀having฀committed฀a฀violent฀crime฀or฀having฀repeatedly฀offended฀ [55] .฀