Sensation & Perception - Ch. 1 Notes

8/12/2019 Sensation & Perception - Ch. 1 Notes

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B334 Lecture 2

INTRODUCTIONBackground to Study of Perception

ORIGINS OF PSYCHOOGY

Fro! p"i#o$op"y and $cience

PHIOSOPHYt"roug"out "u!an "i$tory% t"e in&e$tigation of cau$e$ and #a'$ under#ying reality

SCI(NC()*t" century and ear#y +,t" centuryPhysiology- $tudy of t"e function$ of #i&ing organi$!$ and t"eir part$Psychophysics- $tudy of re#ation$"ip$ .et'een p"y$ica# and p$yc"o#ogica# e&ent$

PSYCHOPHYSICST"e $cience of defining /uantitati&e re#ation$"ip$ .et'een p"y$ica# and p$yc"o#ogica#0$u.1ecti&e2 e&ent$

PSYCHOPHYSICS- F(CHN(RP"i#o$op"y #ead$ to $cientific $tudy of perception in )*t" CenturyGu$ta& Fec"ner 0)3,)4)3352 in&ented 6p$yc"op"y$ic$%7 t"oug"t to .e t"e true founderof e8peri!enta# p$yc"o#ogyPioneering 'ork re#ating c"ange$ in t"e p"y$ica# 'or#d to c"ange$ in our p$yc"o#ogica#e8perience$

PSYCHOPHYSICS- 9(B(R

Fec"ner in$pired .y (rn$t 9e.er 0)5*:4)3532-9e.er $tudied $en$e of touc" u$ingTwo-point threshold: T"e !ini!u! di$tance at '"ic" t'o $ti!u#i 0e;g;% t'o$i!u#taneou$ touc"e$2 can .e di$tingui$"ed

9e.er $tudied 1udg!ent$ of #ifted 'eig"t$JND 0<u$t Noticea.#e Difference2- T"e $!a##e$t detecta.#e difference .et'een t'o$ti!u#i% or t"e !ini!u! c"ange in a $ti!u#u$ t"at can .e correct#y 1udged a$ differentfro! a reference $ti!u#u$; =#$o kno'n a$ difference t"re$"o#d

Di$co&ered t"at t"e $!a##e$t c"ange in a $ti!u#u$% $uc" a$ t"e 'eig"t of an o.1ect% t"at

can .e detected i$ a con$tant proportion of t"e $ti!u#u$ #e&e# >69e.er?$ a'7For 'eig"t- )-@,Standard @,g C"ange needed )gStandard @,,g C"ange needed ),g

Fec"ner e8panded 9e.er?$ 'ork to createFechner’s Law: = princip#e de$cri.ing t"e re#ation$"ip .et'een $ti!u#u$ !agnitudeand re$u#ting $en$ation !agnitude $uc" t"at t"e !agnitude of $u.1ecti&e $en$ationincrea$e$ proportiona##y to t"e #ogarit"! of t"e $ti!u#u$ inten$ity

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B334 Lecture 2

T"at i$% a$ $ti!u#u$ inten$ity gro'$ #arger% #arger c"ange$ are re/uired for t"e c"ange$to .e detected .y t"e percei&er

=BSOUT( THR(SHODSAini!u! a!ount of $ti!u#ation nece$$ary for a per$on to detect a $ti!u#u$ :, of t"e

ti!e

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B334 Lecture 2

PSYCHOPHYSIC= A(THODS

Method of constant stimuli!any $ti!u#i of different inten$itie$ pre$ented rando!#ye;g;% "earing te$t$u.1ect report$ '"et"er t"ey "ear tone or not

Method of limits$ti!u#i 0e;g;% tone2 pre$ented in order of increa$ing or decrea$ing inten$ity=$cending- $u.1ect$ report '"en fir$t "ear t"e toneDe$cending- $u.1ect$ report '"en tone i$ no #onger audi.#e

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B334 Lecture 2

O&er$"oot 'it" !et"od of #i!it$

Method of adustment#ike !et"od of #i!it$ e8cept $u.1ect contro#$ t"e c"ange in t"e $ti!u#u$e;g;% di!!er $'itc" for a #ig"t

Magnitude estimationt"e participant a$$ign$ &a#ue$ according to t"e percei&ed !agnitude$ of t"e $ti!u#u$Rate$ t"e !agnitude on a $ca#e or co!pare$ to ot"er $en$e !oda#ity

!"#N$L D%T%&T"'N T(%')*

= p$yc"op"y$ica# t"eory t"at /uantifie$ t"e re$pon$e of an o.$er&er to t"e pre$entationof a $igna# in t"e pre$ence of noi$eNoi$e- 'it"in t"e $u.1ect and en&iron!enta#

!ignal detection outcomes:

when a stimulus is present:a hit : correctly state stimulus is present

a miss: incorrectly state stimulus is not present

when a stimulus is not present:

a false alarm: incorrectly state stimulus is presenta correct rejection: correctly state stimulus is not present

+,th and %arly .th &entury Physiology

(ar#y p"i#o$op"er$ cou#d on#y $pecu#ate a.out t"e .rain and ner&ou$ $y$te!;

Greek anato!i$t$ Herop"i#u$ 0:+3, BC(2 and Ga#en 0),+,,2 .e#ie&ed t"e !ind

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B334 Lecture 2

'a$ #ocated in t"e .raindi$agreeing 'it" =ri$tot#e 0t"oug"t !ind 'a$ in t"e "eart2.ut e!p"a$iEed t"e f#uid$ in t"e $y$te! 0vital spirit, animal spirit 2 $o focu$ed ont"e &entric#e$ a$ t"e #ocation of t"e !ind

Hydrau#ic 0ani!a# $pirit$2 !ode# 'a$ rep#aced .y a ne' kid on t"e .#ock- (#ectricity

),, p"y$ici$t and p"y$ician 9i##ia! Gi#.ert pu.#i$"e$ De Magnette% fir$t .ook one#ectricity;

)5,,$ Ben Frank#in $tudied e#ectricity

Luigi #al/ani ca+01.Found t"at a frog?$ #eg t'itc"ed '"en one of it$ ner&e?$ recei&ed an e#ectrica# c"arge;

&ount $lessandro 2olta 3ca +1..4!ade fir$t re#ia.#e .attery

in&ent$ !et"od of !ea$uring e#ectric current- ga#&ano!eter

%mil du 5ois-)eymond 3+1+1-+1,64ner&e$ and !u$c#e ti$$ue are c"arged 'it" po$iti&e and negati&e partic#e$t"e$e partic#e$ re&er$e t"eir po$ition$ '"en ner&e$ are $ti!u#ated 0no' ca##ed t"eaction potential 2

(erman /on (elmholt7 3+1+-+1,84

Trained a$ a $urgeon6$e#ftaug"t7 a$ p"y$ici$t and p"y$io#ogi$t

Hig"#y inf#uenced .y <o"anne$ Au##er 0!ore on Au##er #ater2

Measuring !peed of the Ner/e "mpulse($ti!ate$ &ariedAu##er t"oug"t it 'a$ c#o$e to t"e $peed of #ig"t

He#!"o#tE carried out + $tudie$-); U$ed frog !otor neuron$ of different #engt"$ andpendu#u! !yograp" 0"i$ in&ention2 t"at accurate#y !ea$ured !u$c#e contraction$;Co!pared ti!e .et'een $ti!u#ation of ner&e and !u$c#e contraction in #ong ner&e$and $"ort ner&e$Found $peed of conduction *, ft$ec 0!uc" $#o'er t"an $peed of #ig"t2

+; ater He#!"o#tE carried out $tudy 'it" "u!an$Sti!u#ated eit"er toe or t"ig"Su.1ect pre$$ed .utton '"en "e fe#t t"e $ti!u#ationReaction ti!e #onger 'it" greater di$tance tra&e##edSu.tracted t"ig" ti!e fro! toe ti!e($ti!ate of $peed of conduction )@, ft$ec

"dea that ner/es ha/e specific functions

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B334 Lecture 2

Doctrine of specific ner/e energies 0<o"anne$ A##er% )3,)4)3:32- t"e nature of a$en$ation depend$ on '"ic" $en$ory fi.er$ are $ti!u#ated% not on "o' fi.er$ are$ti!u#ated

$lso locali7ation of function to different parts of the 9rain:e;g;% Pierre F#ouren$Studied .rain function in ani!a#$

$ccidental a9lation: &ase studies

Phineas #age)3@3 accident '"i#e 'orking on rai#roadPre!ature e8p#o$ion $end$ ta!ping rod t"roug" "i$ "ead% da!aged fronta# #o.e$Treated .y Dr; <o"n Har#o'Sur&i&ed .ut c"anged per$ona#ity 6no #onger Gage7

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B334 Lecture 2

ack of initiati&e% ina.i#ity to carry t"roug" p#an$;

Locali7ation of Language $reasPierre Paul 5roca 3+18-+11.4

Treated patient '"o under$tood #anguage % .ut cou#d not co!!unicateOn autop$y found da!age in #eft fronta# areaNo' ca##ed Broca?$ area-Broca?$ ap"a$ia- difficu#ty e8pre$$ing one$e#f in a per$on 'it" intact #anguageco!pre"en$ion

Neuron Doctrine or Ner/e Networ 3reticular hypothesis4;neuron$ a$ indi&idua# functioning unit$&$;idea t"at a## ner&e$ inc#uding .rain for! an interconnected net'orkoca#iEation of function &$; non#oca#iEation of function

&ammillo #olgi 3+18<-+,864 de&e#oped $tain to &i$ua#iEe indi&idua# neuron$ .utconc#uded a## neuron$ 'ere direct#y connected

!antiago )amon y &aal 3+1=-+,<84Studied 0and !ade dra'ing$ of2 .rain $#ice$ under !icro$cope% conc#uded neuron$ notdirect#y connected 0$!a## gap2

!ir &harles !herrington 3+1=0-+,=4Studied #eg 'it"dra'a# ref#e8 in dog$% conc#uded ref#e8 con$i$t$ of-$en$ory neuron interneuron !otor neuronGap$ .et'een neuron$ $#o' $peed of ref#e8

Ca##ed gap$ $ynap$e$

!ynapse: T"e 1unction .et'een neuron$ t"at per!it$ infor!ation tran$fer

'tto Loewi 3+10<-+,6+4(8peri!ent 'it" frog "eart$% e&idence for Neurotransmitters: = c"e!ica# $u.$tance u$ed in neurona# co!!unication at$ynap$e$

!ir $llan (odgin 3+,+8-+,,14 and !ir $ndrew (u>ley 3+,+0-4'ork 'it" giant $/uid a8on$di$co&ered "o' ner&e i!pu#$e$ tra&e# a#ong a8onaction potential? an e#ectroc"e!ica# proce$$

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B334 Lecture 2

5rain scans@ neuroimaging techniAues-

a##o' $tudy of .rain acti&ity corre#ated 'it" $en$ation and perception

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Sensation & Perception - Ch. 1 Notes