Work­ing mem­ory (WM) is the cog­ni­tive sys­tem respon­si­ble for the tem­po­rary stor­age and manip­u­la­tion of infor­ma­tion and plays an impor­tant role in both learn­ing and focus­ing atten­tion. Con­sid­er­able research has doc­u­mented that many chil­dren and adults with ADHD have WM deficits and that this con­tributes to dif­fi­cul­ties asso­ci­ated with the dis­or­der. For an excel­lent intro­duc­tion to the role of WM deficits in ADHD, click here.

A sim­ple exam­ple illus­trates the impor­tance of WM for par­tic­u­lar aca­d­e­mic tasks. Try adding 3 and 9 in your head. That was prob­a­bly easy for you. Now try­ing adding 33 and 99. That was prob­a­bly more dif­fi­cult. Finally, try adding 333 and 999. This is quite chal­leng­ing for most adults even though each cal­cu­la­tion required is triv­ially easy. The chal­lenge occurred because you need to store infor­ma­tion — the sum of 3+9 in the one’s col­umn and then ten’s col­umn — as you process the remain­ing part of the prob­lem, i.e., 3+9 in the hundred’s col­umn, and this taxed your WM. If your WM capac­ity was exceeded, you could not com­plete the prob­lem successfully.

This sim­ple prob­lem also illus­trates the dif­fer­ence between short-term mem­ory (STM) and WM. Short-term mem­ory sim­ply involves retain­ing infor­ma­tion in mind for short peri­ods of time, e.g., remem­ber­ing that the prob­lem you need to solve is 333+999. Work­ing mem­ory, in con­trast, involves men­tally manip­u­lat­ing — or ‘work­ing’ with — retained infor­ma­tion and comes into play in a wide range of learn­ing activ­i­ties. For exam­ple, to answer ques­tions about a sci­ence chap­ter, a child not only has to cor­rectly retain fac­tual infor­ma­tion but must men­tally work with that infor­ma­tion to answer ques­tions about it. Thus, when a child’s WM capac­ity is low rel­a­tive to peers, aca­d­e­mic per­for­mance is likely to be com­pro­mised in mul­ti­ple areas.

Because WM deficits play an impor­tant role in the strug­gles expe­ri­enced by many indi­vid­u­als with ADHD, it is impor­tant to con­sider how dif­fer­ent inter­ven­tions address this aspect of the dis­or­der. In this study, the authors were inter­ested in com­par­ing the impact of Work­ing Mem­ory Train­ing and stim­u­lant med­ica­tion treat­ment on the WM per­for­mance of chil­dren diag­nosed with ADHD.

Par­tic­i­pants were 25 8–11 year-old chil­dren with ADHD (21 boy and 4 girls) who were being treated with stim­u­lant med­ica­tion. Children’s mem­ory per­for­mance was assessed on 4 occa­sions using the Auto­mated Work­ing Mem­ory Assess­ment (AWMA), a com­put­er­ized test that mea­sures ver­bal short-term mem­ory, ver­bal work­ing mem­ory, visuo-spatial short-term mem­ory, and visuo-spatial work­ing memory.

At time 1, the assess­ment was con­ducted when chil­dren had been off med­ica­tion for at least 24 hours. The sec­ond assess­ment occurred an aver­age of 5 months later and when chil­dren were on med­ica­tion. The third assess­ment occurred after chil­dren had com­pleted 5 weeks of Cogmed Work­ing Mem­ory Train­ing using the stan­dard train­ing pro­to­col (see below). The final assess­ment occurred approx­i­mately 6 months after train­ing had ended. This design enabled the researchers to make the fol­low­ing comparisons:

- WM per­for­mance on med­ica­tion vs. off med­ica­tion (T1 vs T2)
– WM per­for­mance on med­ica­tion vs. after train­ing (T2 vs. T3)
– WM per­for­mance imme­di­ately after train­ing ended vs. 6 months fol­low­ing train­ing (T3 vs. T4)

This final com­par­i­son pro­vided infor­ma­tion on whether any ben­e­fits pro­vided by the train­ing had endured.

In addi­tion to mea­sur­ing STM and WM at each time point, mea­sures of IQ were col­lected at times 1, 2, and 3.

- Work­ing Mem­ory Train­ing -

WM train­ing was con­ducted using the stan­dard Cogmed train­ing pro­to­col with each child com­plet­ing 20–25 train­ing ses­sions within a 25 day period. The train­ing requires the stor­age and manip­u­la­tion of sequences of ver­bal, e.g., repeat­ing back a sequence of dig­its in reverse order, and/or visuo-spatial infor­ma­tion, e.g., recall­ing the loca­tion of objects on dif­fer­ent por­tions of the com­puter screen.

Dif­fi­culty level is cal­i­brated on a trial by trial basis so the child is always work­ing at a level that closely matches their per­for­mance. For exam­ple, if a child suc­cess­fully recalled three dig­its in reverse order, on the next trial he had to recall four. When a trial was failed, the next trial was made eas­ier by reduc­ing the num­ber of items to be recalled. This method of ‘adap­tive train­ing’ is thought to be a key ele­ment because it requires the child to ‘stretch’ their WM capac­ity to move through the program.

- Results -

- Impact of Short-Term Mem­ory and Work­ing Mem­ory -

Med­ica­tion vs. no med­ica­tion — When tested on med­ica­tion, Read the rest of this entry »

Neu­ro­feed­back — also known as EEG Biofeed­back — is an approach for treat­ing ADHD in which indi­vid­u­als are pro­vided real-time feed­back on their brain­wave pat­terns and taught to alter their typ­i­cal EEG pat­tern to one that is con­sis­tent with a focused, atten­tive state. This is typ­i­cally done by col­lect­ing EEG data from indi­vid­u­als as they focus on stim­uli pre­sented on a com­puter screen. Their abil­ity to con­trol the stim­uli, for exam­ple, keep­ing the smile on a smi­ley face, is con­tin­gent on main­tain­ing the par­tic­u­lar EEG state being trained. Accord­ing to neu­ro­feed­back pro­po­nents, learn­ing how to do this dur­ing train­ing gen­er­al­izes to real world sit­u­a­tions and this results in improved atten­tion and reduced hyperactive/impulsive behavior.

Neu­ro­feed­back treat­ment for ADHD has been con­tro­ver­sial in the field for many years and remains so today. Although a num­ber of pub­lished stud­ies have reported pos­i­tive results many promi­nent ADHD researchers believe that prob­lems with the design of these stud­ies pre­clude con­clud­ing that neu­ro­feed­back is an effec­tive treat­ment. These lim­i­ta­tions have included the absence of ran­dom assign­ment, the lack of appro­pri­ate con­trol groups, raters who are not ‘blind’ to children’s treat­ment sta­tus, and small sam­ples. For addi­tional back­ground, you can find a recent review I wrote on exist­ing research sup­port for neu­ro­feed­back treat­ment of ADHD — along with links to exten­sive reviews of sev­eral recently pub­lished stud­ies -: How Strong is the Research Sup­port for Neu­ro­feed­back in Atten­tion Deficits?

- Results from a New Study of Neurofeedback -

Recently, a study of neu­ro­feed­back treat­ment for ADHD was pub­lished that addresses sev­eral lim­i­ta­tions that have under­mined prior research [Gevensleben, et al., (2009). Is neu­ro­feed­back an effi­ca­cious treat­ment for ADHD? A ran­dom­ized con­trolled clin­i­cal trial. Jour­nal of Child Psy­chol­ogy and Psychiatry.]

The study was con­ducted in Ger­many and began with 102 chil­dren aged 8 to 12. All had been care­fully diag­nosed with ADHD and approx­i­mately over 90% had never received med­ica­tion treat­ment. About 80% were boys. Chil­dren were ran­domly assigned to Read the rest of this entry »

Like all psy­chi­atric dis­or­ders, ADHD is diag­nosed based on the pres­ence of par­tic­u­lar behav­ioral symp­toms that are judged to cause sig­nif­i­cant impair­ment in an individual’s func­tion­ing, and not on the results of a spe­cific test. In fact, recently pub­lished ADHD eval­u­a­tion guide­lines from the Amer­i­can Acad­emy of Pedi­atrics (AAP) explic­itly state that no par­tic­u­lar diag­nos­tic test should be rou­tinely used when eval­u­at­ing a child for ADHD.

While most ADHD experts would agree that no sin­gle test could or should be used in iso­la­tion to diag­nose ADHD, there are sev­eral impor­tant rea­sons why the avail­abil­ity of an accu­rate objec­tive test would be useful.

First, many chil­dren do not receive a care­ful and com­pre­hen­sive assess­ment for ADHD but are instead diag­nosed with based on eval­u­a­tion pro­ce­dures that are far from optimal.

Sec­ond, although AAP guide­lines indi­cate that spe­cific diag­nos­tic tests should not be rou­tinely used, many par­ents are con­cerned about the lack of objec­tive pro­ce­dures in their child’s eval­u­a­tion. In fact, many fam­i­lies do not pur­sue treat­ment for ADHD because the the absence of objec­tive eval­u­a­tion pro­ce­dures leads them to ques­tion the diag­no­sis. You can read a review of an inter­est­ing study on this issue at www.helpforadd.com/2006/january.htm

For these rea­sons an accu­rate and objec­tive diag­nos­tic test for ADHD could be of value in many clin­i­cal sit­u­a­tions. Two impor­tant con­di­tions would have to be met for such a test to be useful.

First, it would have to be highly sen­si­tive to Read the rest of this entry »

We have talked about the value of med­i­ta­tion before (see Mind­ful­ness and Med­i­ta­tion in Schools), as a form of well-directed men­tal exer­cise than can help train atten­tion and emo­tional self-regulation.  Which other stud­ies have shown how it strength­ens spe­cific parts of the brain, mainly in the frontal lobe.

Dr. Rabiner shares with us, below, an excel­lent review of a new study that ana­lyzes the ben­e­fits of mind­ful­ness for ado­les­cents and adults with atten­tion deficits. He writes that “although this is clearly a pre­lim­i­nary study, the results are both inter­est­ing and encouraging.”

- Alvaro

Does Mind­ful­ness Med­i­ta­tion Help Adults & Teens with ADHD

– By Dr. David Rabiner

Although med­ica­tion treat­ment is effec­tive for many indi­vid­u­als with ADHD, includ­ing ado­les­cents adults, there remains an under­stand­able need to explore and develop inter­ven­tions that can com­ple­ment or even sub­sti­tute for med­ica­tion. This is true for a vari­ety of rea­sons includ­ing:
1) Not all adults with ADHD ben­e­fit from med­ica­tion.
2) Among those who ben­e­fit, many have resid­ual dif­fi­cul­ties that need to be addressed via other means.
3) Some adults with ADHD expe­ri­ence adverse effects that pre­vent them from remain­ing on medication.

Read the rest of this entry »

A very promis­ing cog­ni­tive train­ing study was pre­sented last week by Helena West­er­berg at the annual meet­ing of the CNS: Cog­ni­tive Neu­ro­science Soci­ety held in San Fran­cisco, and Dr. David Rabiner brings us the highlights.

- Alvaro

———————

The study was con­ducted with a gen­eral adult pop­u­la­tion, rather than adults diag­nosed with ADHD, as was the case in pre­vi­ous pub­lished work­ing mem­ory train­ing studies,

The study was a ran­dom­ized, con­trolled trial of work­ing mem­ory train­ing con­ducted with 55 younger (20–30 years old) and 45 older (60–70 years old) adults. Par­tic­i­pants were ran­domly assigned to receive 5 weeks of active Cogmed Work­ing Mem­ory Train­ing or a placebo train­ing inter­ven­tion. In the active train­ing group, the dif­fi­culty of the work­ing mem­ory train­ing tasks con­tin­u­ally adjusted to match the individual’s per­for­mance. As a result, indi­vid­u­als were con­sis­tently chal­lenged to per­form at their high­est pos­si­ble level. In the placebo train­ing group, the dif­fi­culty level remained con­stant across the train­ing period such that improve­ments in work­ing mem­ory were not expected to occur.

Read the rest of this entry »

A CDC report esti­mated that, in 2003, 4.4 mil­lion youth ages 4–17 lived with diag­nosed ADHD, and 2.5 mil­lion of them were receiv­ing med­ica­tion treat­ment. Now, which is the core deficit under­ly­ing ADHD-so that treat­ments really address it? and how are ADHD and brain devel­op­ment related? Keep reading…

ADHD & the Nature of Self-Control — Revis­it­ing Barkley’s The­ory of ADHD

— By David Rabiner, Ph.D

As implied in the title of his book, ADHD and the Nature of Self-Control, Dr. Barkley argues that the fun­da­men­tal deficit in indi­vid­u­als with ADHD is one of self-control, and that prob­lems with atten­tion are a sec­ondary char­ac­ter­is­tic of the disorder.

Dr. Barkley empha­sizes that dur­ing the course of devel­op­ment, con­trol over a child’s behav­ior grad­u­ally shifts from exter­nal sources to being increas­ingly gov­erned by inter­nal rules and stan­dards. Con­trol­ling one’s behav­ior by inter­nal rules and stan­dards is what is meant by the term “self-control”.

Read the rest of this entry »

As we have been doing for the last 6 months, here you are have the Monthly Digest of our Most Pop­u­lar Blog Posts. You can con­sider it your monthly Brain Fitness/ Train­ing Newsletter.